Intro to Force Measurement
Force measurement in the United States has had an interesting history. This article discusses the history of force measurement from the 1800s through post-World War II. Let’s take a look.
All information presented here is drawn from “Measures For Progress: A History of The National Bureau of Standards” (Rexmond C. Cochrane).
Regulating Standards of Measurement
The need to regulate standards of measurement in the United States arose in the late 19th century amid the phenomenal growth of industry and the pace of invention the country was experiencing. The engineers and scientists behind the production and dissemination of such inventions as the automobile and electricity needed to test their inventions. In order to do this, they needed standards of measurement. Consumers also cried out for regulation and standardization of commodities produced by different manufacturers. The lack of uniform standards was also a problem in government. For example, when imposing import taxes, the same quantity of goods might be found to weigh more at one port of entry than another, as evidenced in an 1832 investigation which found that “no two customhouses in the country” had the same weights.
The founding fathers’ aversion to centralized power and control prevented earlier establishment of government standards, despite the fact that governments in Europe had long supported such measures. The federal government did not support any scientific measurement until the establishment of the Coast and Geodetic Survey was founded in 1807. In 1836, the Office of Weights and Measures was born within the Survey. Gradually, different government agencies developed their own research departments for things like medical research (Army), meteorology (Navy), telegraph facilities (Army), etc. In the world of academia, research was also taking place. At times, researchers within these contexts set up their own means of taking measurements, with the result that differing standards arose for the “same” measurement. William Mason of the Rensselaer Polytechnic Institute found eight different ‘authoritative’ values for the gallon, so to avoid confusion, he made up his own value for the gallon. Similarly, city surveyors in Brooklyn in 1902 recognized four different ‘feet’ as legal.
Eventually, a Congressional commission was established to evaluate the method by which research was conducted within government agencies. It found that work was being overlapped and duplicated by various agencies. As a result, the National Academy of Sciences was recommended to centralize research for government purposes, but fears of government encroachment on the free market ultimately killed the proposal.
The first real attempt by the government to standardize weights and measures came in 1836 when Ferdinand Hassler, superintendent of the Coast Survey in the Treasury Department, was directed by the Secretary of the Treasury to produce copies of various standards. Congress was still reluctant to enact a law making use of the measures obligatory, but they did approve the standards and instruct that copies be delivered to the governors in every state. Enforcement of their use, however, was not obligatory and laws continued to be passed at the state and federal levels defining new standards.
The new electrical industry was particularly affected by the lack of good standards. Laboratory testing was performed by trial and error, costing the industry dearly in time and resources, because accurate instruments did not exist for performing such experiments. At the turn of the century, electricity was a $200 million enterprise but its growth was slowed by the fact that it was frequently engaged in lawsuits for want of industry standards. As the United States was the world leader in electrical invention, instruments were created in this country for electrical testing, but users in Europe would calibrate the instruments themselves, because the US manufacturers’ standards were unknown. Measuring apparatus for all kinds of applications were regularly sent from the US abroad to be calibrated and verified in international laboratories, whose standards could be trusted, as opposed to having these services performed domestically. This eventually became viewed as a disgrace to the nation, to say nothing of the time wasted and money paid abroad for these services which should be performed within the US itself.
In 1899, work began to draft a bill for presentation to Congress proposing legalization of better standards and enforcement of their use. It was supported by numerous associations and institutes concerned with scientific pursuits. Representatives from manufacturing, government, and educational institutions spoke out via testimony and written endorsement for the need to enact such a bill. The proposal advocated reorganization of the Office of Standard Weights and Measures into the National Standardizing Bureau to be under the Secretary of the Treasury and that the new agency would have 6 primary functions:
- custody of the standards
- the comparison of the standards used in scientific investigations, engineering, manufacturing, commerce, and educational institutions with the standards adopted or recognized by the Government
- the construction when necessary of standards, their multiples and subdivisions
- the testing and calibration of standard-measuring apparatus
- the solution of problems which arise in connection with standards
- the determining of physical constants, and the properties of materials when such data are of great importance to scientific or manufacturing interests and are not to be obtained of sufficient accuracy elsewhere.
Early Years of the Bureau of Standards
Between the law’s passage and its enactment, Dr. Samuel Wesley Stratton, the author of the letter that persuaded congress, was named Director of the agency and set to work locating premises for the offices, commissioning the buildings that would house the Bureau, seeking out qualified personnel, ordering the equipment that would be needed to perform the tasks necessary of the Bureau, and visiting laboratories abroad upon which the Bureau would be modeled. He had majored in mechanical engineering at the University of Illinois and later became an instructor and professor in the fields of math, physics and electrical engineering. He was also awarded six honorary doctorates from various institutions including Cambridge and Yale. Dr. Stratton would head the Bureau for 21 years and personally oversee its development into one of the best agencies of its kind in the world.
For much of its early years, the Bureau’s energies were almost wholly engaged in developing its staff and organization and establishing new and much needed standards for science and industry. The equipment necessary for testing was ordered in Paris and Berlin and Stratton visited the International Bureau of Weights and Measures as well as the leading laboratories across Europe. Other members of the Bureau made similar visits during the early years. Dr. Edward Rosa was hired from Wesleyan University to plan and direct the electrical research which had been so fundamental to the need for the Bureau. Stratton and Rosa believed it to be of the upmost importance and accordingly the Bureau provided Rosa with the best equipment available. Rosa published more than 75 papers during his time at the Bureau and demanded the same work ethic of his subordinates.
It was decided that the Bureau would be split into scientific and technical divisions. They also established a “Secretary’s Visiting Committee” on which served leaders in science and industry to annually report to the Bureau on matters of interest to its scope of influence. Invitations were sent to the chief electrical engineer at GE, the president of MIT and a professor of physics at Cornell, in addition to several others.
In 1903, the National Bureau of Standards was transferred from the Treasury Department to the Department of Commerce and rechristened the “Bureau of Standards”, dropping the “National” from its name. With this administrative change, the Bureau’s scope increased far beyond what it likely would have been in the Treasury to include active participation in the business sector.
After about 3 years, the Bureau had obtained sufficient instrumentation and staff to begin its real work. In the year prior to the establishment of the National Bureau of Standards, the Office of Standard Weights and Measures reported that it had compared 65 thermometers and 69 surveyors’ tapes, had graduated and verified 772 sugar flasks, replied to 75 requests for information, and with routine weights, measures, and balance tests, had answered a total of 1,037 “calls” on it – all this while still having to send instruments abroad to Germany or England for verification of their accuracy. Within the first 3-4 years, In addition to all the work on standards, instrumentation, and planning of research in that period, the number of tests made for universities, industry, and Government agencies had increased eight times over that possible in the former Office and would more than double again within another year. One of the early projects of the engineering instruments section was to test gas meters, water meters, pressure gages and other instruments used by public utilities. This was one of the first large scale projects undertaken by the Bureau for the common good. Another early undertaking was testing on building materials.
Other early work of the Bureau included establishment of a standard of inductance, which impacted new developments in the communications industry.
In a little more than 3 years, Stratton had assembled the men and materials for an organization that, “judged by the magnitude and importance of the output of testing and investigation,” said Rosa, “ranked second only to the great German Reichsanstalt among the government laboratories of the world doing this kind of work.”
Staffing Problems at the Bureau of Standards
In 1909, the structural materials laboratories of the Geological Survey were transferred to the Bureau of Standards, which added 53 staff members and four field laboratories, with the Bureau later adding a fifth (as no more space was available in the two buildings originally planned to house the Bureau and its laboratories). Around this time appropriations were made for new large capacity (up to 2.3 million pounds) testing machines, to be used mainly in testing construction materials, and a new building to house them.
The Bureau was troubled by the difficulty to find and keep staff members. As the Bureau’s prestige grew, its personnel were presented with offers from universities and private laboratories eager to add staff with Bureau training to their ranks. They were willing to pay double or more what Government appropriations allowed for the salaries of Bureau employees, forcing the Bureau to hire recent graduates and relatively inexperienced staff, train them on the job and then promote from within. As a perk of working for the Bureau, a doctoral program was instituted in which employees could attend night classes taught by senior staff or professors visiting from nearby universities and where students could use the work they were doing for the Bureau toward their theses. As an additional lure for students, the Bureau offered testing opportunities and equipment that no other university in the country could. The program was a success offering 72 graduate and undergraduate courses by 1960 with over 1,300 enrollees at that time.
Measurement Regulations for Power
In the 20 years from 1899 to 1919, use of electricity as a power source for American industry had jumped from less than 5% to more than 55%. Dr. Rosa, as head of the Bureau’s electrical research division, once said that the Bureau came into being largely to aid the new electrical industry. He felt that by the Bureau’s involvement, the quality of the products, instruments and machinery produced by this industry was increased and by demanding a higher quality product for the marketplace, the public also benefited from the Bureau’s work. In the Bureau’s earliest days, almost half of the new staff members to the Bureau were dedicated to the electrical research division to work on research in radio, electrolysis, electrochemistry and more. The first order of business was to create/definite/improve standards of electrical measurement, which saw huge progress between 1903-1910. Work conducted at the Bureau in Washington in 1910 yielded the first internationally accepted high-precision standards for electrical units, which would stand for some 37 years.
By 1925, technology and measurement technique had advanced to the point that the standards developed in 1910 were no longer satisfactory. A movement began to establish new standards in terms of absolute measurement – that is, measurement based on the absolute values of the centimeter, gram and second (CGS). The Bureau’s electrical division once again set to work developing standards within this framework.
During this era, public utilities, such as gas and electric companies lacked ethical standards as much as measurement standards. Accusations of fraudulent meters, inferior product and unchecked rates were made against providers of gas, electricity, railways and others. The Bureau, working in conjunction with these companies, found that in some cases, the companies were not entirely at fault, but rather were at the mercy of lacking uniformity in standards and specifications for their product. Beginning with investigations in lamp lighting (from setting standards for incandescent bulbs, to testing the illuminating power of varying kerosene samples), the Bureau was instrumental in revising the public utility system. The Bureau’s work on gas for illumination led to work on standards for gas used for heating purposes as well. By recommending that gas be sold by its heating value (Btu), instead of the volume sold, the Bureau in effect forced the gas companies to sell a better product, free from impurities like nitrogen that did not contribute to the heating value. Gas companies argued that use of the heating value was not applicable to efficacy of gas used for lighting purposes, but Bureau research directly showed that heating value was an accurate measure of usefulness to the consumer, even if the consumer’s use was lighting rather than heat.
Later investigations into other gas-powered appliances lead to improvements in efficiency, safety and sales. Gas continued to be sold by the cubic foot, however, due to the fact that there was no good Btu meter available to the utility companies. Monitoring of gas quality was taken on by state-run laboratories that were equipped with better chemical and caloric test equipment, so gas companies were held accountable by that means.
Having successfully contributed to the imposition of quality and quantity standards in the gas industry, the Bureau later took on the task, at the request of the industry, to provide standards to the electrical utilities. A variety of instruments and techniques were developed to measure current and voltage. In addition, the Bureau tested and calibrated these instruments as well as consumption meters. Later endeavors included the analysis and testing of current transformers for high-voltage power stations (under Dr. Paul Agnew), work on insulating materials, copper wire tables (for the American Institute of Electrical Engineers and numerous other projects supporting the electrical industry.
Standards for the Railroad
The next large project to land on the Bureau’s plate was an investigation into large scales, such as railroad scales used to calculate charges on interstate shipments and grain-hoppers. Particularly in the case of railroad scales, there was little inspection or maintenance done at the state level, which lead to complaints and lawsuits when people felt the scale’s inaccuracy cost them in extra shipping fees. The railroads were left with little choice but to cooperate with the Bureau’s investigation to regain credibility. In 1913, using funds appropriated by Congress, the Bureau built a test rail car, which it then used to begin testing scales in New England and the Mid-Atlantic. Early tests resulted in the rejection 75-80% of the scales tested. A second car was built to be used in the South and Midwest. With the Bureau’s help, procedures were designed and implemented to restore accuracy in large-capacity measurement. The test cars continued their circulation into the 1930s.
Another railroad issue was also brought to the Bureau in 1912. An investigation had been done to determine the number of accidents (deaths, derailments and the like) occurring on the railroads each year. The primary cause of these accidents was determined to be the failure of parts like rails, wheels, flanges and axles. Samples of the failed parts were sent to the Bureau for a variety of tests to determine the source of the weakness causing the breakages. The results showed the reason for rail failure to be fissures on the interior of the rails. The Bureau worked together with the big steel companies to establish standard practices for manufacturing rails (no such standardization existed before this investigation), resulting in a two-thirds drop in the number of accidents by 1930.
Corrosion Laboratory is Established
Yet another problem involved the electrolytic corrosion caused by the trolley system, which comprised 40,000 miles of track in urban areas by 1917. The problem, first discovered in Boston in 1902, was that the current used to power the trolleys, instead of flowing through the tracks back to the generating station as conceptualized, often strayed from the tracks to better conductors, like underground pipes, cables, etc. The result was that the electricity advanced the corrosion of underground pipes, weakening them and leading to breaks, in water mains and sewers, for example. Underground telephone and telegraph wires and light and power cables were also at risk. Perhaps most alarming was the discovery of corrosion to the reinforced concrete supports of bridges, piers and buildings. Aside from the risks to safety and to possible interruption of utility service, financial losses were estimated to be in the millions of dollars due to leakage from gas and water mains and the investment for need repairs. A team assembled at the Bureau to investigate earth electrolysis and possible techniques for addressing its negative effects developed procedures to allow utility engineers to assess the situation independently and also developed an insulated feeder system to reduce corrosion. As a result of continued work on this issue, the Bureau developed an earth-current meter in 1921 which could accurately measure currents responsible for corrosion and the rate of corrosion. Another aspect of the corrosion problem had to do with the corrosive elements within soil itself, without the help of stray electrical current. To continue studying this phenomenon, the Bureau established a Corrosion Laboratory in 1922.
The corrosion problem was not solely the result of man-made electrical currents. As such, the Bureau, encouraged by gas companies and other utilities, continued to investigate the issue of corrosion due to the soil in which metallic infrastructure was buried, absent of any electrical current.
Bureau of Standards Creates Utility Standards
Another industry that sought the aid of the Bureau was the coal mining industry, which approached the Bureau in 1909 seeking help in establishing standards of electrical practice in mines. One of the first industries to adopt practices utilizing the benefits of electricity, the mining industry quickly found that electrical sparks in the mines could quickly lead to disasters. The mining question led the Bureau to do a more comprehensive assessment of the hazards posed to life and property by electricity used both in industry and in the home and produced both by man or by lightning. The result was the publication of safety rules for the electrical industry in 1914 and the establishment of a nationwide electrical safety code in 1915. Both publications met with widespread resistance causing the Bureau to issue to circular citing numerous examples of electrical accidents from newspapers published in 1913. In time, however, states and municipalities recognized the need for safety practices and adopted the Bureau’s methods.
Dr. Stratton, meanwhile, argued that the investigations into the electrical industry and electrical safety were not enough and called for similar investigations into all utilities including gas, water and telephone, among others. The Secretary of Commerce agreed and in 1914, Congress appropriated funds for the work. Again, the investigation was met with resistance from the utilities and the public, causing circulars to be issued describing the exact nature and goals of the Bureau’s work and how it would benefit society.
During this time, the Bureau’s appropriations for public utility standards were its second-highest, exceeded by appropriations for industrial research. This testing began with structural materials such as clay and iron and ranged all the way to rubber bands and ink. In first testing the properties of the substance in question, the investigation often progressed into issues related to the manufacture and performance of said substance.
For example, the Bureau tested samples of cement purchased for Government construction projects to see if it met Government specifications. It was quickly discovered that the specifications were vague or contradictory and different agencies followed different specifications. As part of their work to develop a clear standard, the Bureau had to develop new and better testing practices and testing equipment. After developing new procedures and instruments, the Bureau found they needed to further investigate the properties of the cement, which eventually led to the development of an entire experimental manufacturing plant so that researchers could study the effects of different manufacturing processes. This method of research was then carried over to the study of other construction materials. At the same time, other Bureau facilities were conducting tension and compression tests on the concrete and still others were studying the effects of external elements, such as seawater, on the concrete. Each new report on the finding seemed to generate requests from manufacturers, engineers or the public to study some new facet of the concrete, which would then require the establishment of procedures and development of equipment to study each new issue. With each new material subjected to Bureau investigation, the process generally began with a meeting at the Bureau of representatives from the manufacturing, construction, and academic communities as well as other concerned parties to discuss the issues and goals of each regarding the investigation.
The Bureau met with its share of fruitless or unsuccessful testing as well. In one instance a researcher set out to develop a way of conducting quality assurance testing on metals based on their magnetic properties. The goal was to identify flawed material without the need for destruction tests, with the goal of applying the new procedure in instances like those of the fissured track rails. Initial results indicated a correlation between the magnetic and mechanical properties of some metals causing much excitement within the Bureau and the concerned industries; however, years of further testing negated these early findings and the Bureau eventually abandoned the project.
Successes of the Bureau od Standards
In contrast to the unsuccessful magnetic testing, the Bureau had tremendous successes as well. Among their most successful endeavors of the age was the work done on temperature-related issues especially the temperature scale and refrigeration constants. This work began in 1909 when the American Society of Refrigerating Engineers engaged the Bureau’s assistance in collecting data on refrigerants. The heat division then turned its attention to determining constants of gases, combustion points for different substances and so on. As a result of this work, the Bureau was able to fix new points on its standard temperature scale. With an appropriation from Congress in 1913, the Bureau resumed work on refrigeration, this time for large-scale machinery to be used for meat-packing and other cold storage plants. In addition to the study of the specific heats of ice and other refrigerants, the Bureau also investigated insulation and construction concerns related to this large-scale cooling.
Following the appropriation for refrigerant study, Congress approved the next year an appropriation for the study of fire-resistant building materials. Annual losses of life and property due to fire were 10 times higher in American than any country in Europe, according to studies. Even buildings that were declared to be “fire proof” often burned as completely as other buildings in the series of American city fires around the 1900s. As part of this investigation, Bureau engineers reviewed city building codes and found them to be filled with inaccurate data regarding the properties of building materials. For example, codes that claimed brick, mortar, plaster, cement and metal to be uniformly fire resistant did not include testing or data regarding the various compositions of these materials, nor did it consider their response to high temperatures such as would be encountered in a building fire. Soon the heat division of the Bureau had a new section devoted to fire-resistance. The Bureau constructed furnaces, buildings and all sorts of structures and then subjected them to fire testing. They even burned abandoned structures in downtown Washington as part of the research. Their efforts resulted in new standards provided to cities for civil engineering and work on fire-resistance continues at the Bureau to this day.
Publicizing Their Findings
Throughout the course of its existence, the Bureau has sought to make its findings public knowledge for the good of the consumer. In its early days, this goal was accomplished by means of circulars which were printed and then made available for purchase (for a 10 cent fee) to the general public. When the Bureau published its lamp specifications as Circular 13 in 1907, the text was full of scientific terms and anonymous data that did not provide much information to help the consumer know which brand of lamp to purchase at their local store. This was also a problem with later publications on textiles, inks, soaps and other materials used by the average person in the course of their daily life, but the Bureau could not name specific brands without calling into question whether the data had been corrupted by the manufacturers in question.
In 1915, Circular 55 “Measurements for the household” was published. Its sales were more than 6 times higher than its bestselling predecessor and required multiple additional printings and a cheaper version printed on lesser-quality paper. Its success was due to the simple and accessible language used and its content treated household items such as scales, cooking measures and clocks. The Bureau continued to refrain from using brand names or pointing to specific manufactures, but in many cases, the data was presented in such a way that the consumer would infer those details.
The next effort made to the general public was the publication of Circular 70 “Materials for the household,” which was published in 1917. Not as popular as Circular 55, Circular 70 addressed concerns regarding materials used in the home, such as rubber, leather, stationary, building materials, fuels and cleansing agents. It was essentially the forebear of publications like Consumer Reports that American still consult today. Many household products still lacked standards of production or quality standards before they entered the marketplace, a fact recognized by the Bureau. As such, the Bureau made suggestions, where possible, of how to perform quality tests in the home, such as a test the average housewife could perform to determine the strength of thread. When no home test could be offered, the Bureau simply suggested buying from reputable sellers and taking into account the experiences and reviews of other consumers.
Continuing its effort to make relevant knowledge available to the public, the Bureau published a third circular in 1918, Circular 75 “Safety in the household.” So popular and enduring was the first edition, that the Bureau revised the data accordingly and published a second edition in 1932. The focus of “Safety in the household” was to bring awareness to the increasing dangers posed by household use of gas and electricity, newly developed poisons (like cleaning materials), and other safety concerns that came with the boom in invention and availability of an ever-wider range of products to the average consumer.
The combined impact of all three circulars was to leave an impression on the public that the Bureau existed to test household materials and appliances, with the whole scope of the Bureau’s work known only in technical and scientific arenas. In fact, so unaware was the general populace of the Bureau’s full work that Thomas Edison suggested that the government establish a similar entity in 1915 because he didn’t know that it already existed.
Beginning Interest in Radioactivity and Nuclear Physics
Although the Bureau was quick to see the need for its presence in electrical concerns and materials production and standardization, it was somewhat slow to adopt an interest in the field of radioactivity. In 1904, a physics professor came to the Bureau with a book entitled “Radioactivity,” but the Bureau took little interest. Following a second edition of “Radioactivity,” a Nobel Prize to its author Rutherford, and a visit in 1909 to the Bureau by Rutherford himself, the Bureau finally took notice of the future of nuclear physics.
Tangential to radiation, another kind of emanation, radio telegraphy (wireless) was also introduced. The earliest experiments in transmission of sound through radio signals had begun around 1901. Though its existence was known, use of radio was not employed in World War I and it was not really commercially developed until the 1920s. Early work on radio at the Bureau focused on its use in Navy communications as the U.S. Naval Radiotelegraphic Laboratory at the Bureau. Not long after Navy investigations were established, the Army followed suit. For several years, the Bureau housed the investigators from the armed services, before actually beginning work on radio itself in 1911, when a commercial researcher sent in his frequency meter for calibration.
The means for calibrating radio equipment did not exist at the Bureau, so the problem was turned over to their resident wireless expert who soon headed a new section called radio measurements. The first radio-related issue to be tackled in detail was the investigation of ammeters used to measure high frequency current in radio transmitters. This study led to the establishment of heavy-current standards for radio frequencies. For the most part, the army/navy researchers at the Bureau concentrated on low frequency longer transmission signals, the Bureau dedicated the bulk of its early work to high frequency commercial concerns.
In 1912, on the eve of a Wireless Conference in London (to which the Bureau would send a representative), the sinking of the Titanic showed how useful radio could be and how badly trained operators were needed. Four ships were within 60 miles of Titanic when radio operators sent their first distress signals, but inexperienced operators had trouble receiving the messages or were not manning their radios at the time. Only one of the ships responded to Titanic’s signals.
For the most part, the degree to which human error in use of radio had contributed to the loss of life in the Titanic disaster remained unknown, but the Wireless Conference in London did determine that only the 600-meter wavelength would be used for ships at sea and it set other standards in place regarding radio transmission at sea.
Following the Conference, Congress began to create legislation governing the use of radio, including laws over wavelength usage and licensing of radio stations. These concerns fell to the Bureau of Navigation (within the Department of Commerce) which called on the Bureau of Standards to supply Congress with more information including test procedures and standards related to radio use. In order to enforce Congress’s law on interference, the Bureau designed a decremeter to measure wavelength and decrement. His instrument was immediately accepted for use by the Bureau of Navigation as well as the War and Navy Departments. From 1913-1915, the Bureau developed a radio compass system to aid ship navigation (though its implementation was slow due to resistance from the Bureau of Lighthouses and from ship captains). In 1915, Congress appropriated funds to support investigation and standardization within the new radio industry. This was followed by a larger appropriation in 1916 for construction of a radio laboratory.
Initial Research on Radioactivity
We left off with the Bureau’s early introduction into radio research, but research into radioactivity also started around the same time. Initial research on radioactivity, which began years later in the laboratories of the United States than in Europe, was conducted under the Bureau’s electrical division. A Congress had been held in Brussels regarding radiology and an international standard had been accepted for radium, before the first sampling (20.28 milligrams) of radium arrived at the Bureau.
A researcher named Dorsey, who had come to the Bureau from Johns Hopkins, had followed the international research on radiation prior to the Bureau’s own research and was particularly interested in its possible medical application. Dorsey became the Bureau’s radiation specialist, but because the effects of handling the radioactive materials he worked with were not yet understood, Dorsey suffered permanent damage to his hands and left the Bureau in 1920. He published a book on radioactivity for use by medical professionals before returning to the Bureau in 1928 to continue his research in physics and act as a consultant to the radium and X-ray section of the optics division.
Increasing Reach of the Bureau
At this point in the Bureau’s development, after a little more than a decade, the Bureau had grown from 13 employees to 280 working on over 200 projects for the government, public utilities and private industry, while appropriations had grown from $32,000 to some $500,000 annually and new physical locations and new divisions (engineering research, metallurgy, etc.) had been added. In fact, the Bureau’s scope of work was at that point far broader than imagined at the time of its creation, prompting questions from other Government research agencies as to whether the Bureau was still operating within the bounds of its original act. Congress, however, continued to approve of the Bureau’s work and continued to make special appropriations for research into specific projects.
In response to the criticism from other agencies, Dr. Stratton expressed a wish to revise the wording of the Bureau’s organic act to avoid misinterpretation as to the scope of the Bureau’s domain, but recognized that doing so would cost the Bureau some flexibility. His solution was to create additional seats on the Visiting Committee to the Bureau so that technological and industrial interests would be represented in addition to the scientific representation that already existed. The actual result was an amendment in 1913 to the act that designated the Bureau to test industrial and commercial materials for the government of the District of Columbia.
Also in 1913, William Redfield was appointed Secretary of Commerce and was to become a strong supporter of the Bureau. Redfield visited the Bureau weekly for insight into work that would concern his department. He also made recommendations for consolidating research departments of other agencies into the Bureau when he saw that it would increase efficiency.
It was also under his direction that the format of the Bureau’s annual report changed to include a list of current needs and that far more copies of the report were distributed. A revision was also made to the published scope of the Bureau as found in the report so that it read that the Bureau was responsible for standards of measurement, standard values of constants, standards of quality, standards of mechanical performance and standards of practice. Recognizing that these functions pertained largely to the Government, it was also understood that the needs of the Government and the general public were quite similar. That is to say that if testing were performed and a standard set to determine the best quality product for Government purchase, the same standard would also apply to private purchase of the same item.
World War I and Military Research
At this point, the attentions of the Government and the country turned toward World War I then raging in Europe. The first official wartime research performed by the Bureau related to aeronautic design, and was requested by the National Advisory Committee for Aeronautics. Following this initial endeavor, other requests were made by the War and Navy Departments to conduct research that they were unequipped to perform themselves. Even so, it was a largely unrecognized fact that this war would be one of technology, material and production and that science and technology would play a critical role.
By the time the United States entered the war and realized how many troops and how much equipment would be needed, there was no time for intensive long-term experimentation, so Allied research was adapted to American production methods. Scientists in this country were consumed in the search for new materials, especially new metals for heavy weapons and armor, and replacements for materials made scarce by war use. Chemists were also engaged in production of agents of chemical warfare. Most of these concerns remained outside the scope of the Bureau (with a few exceptions) until 1917 when over $2 million was allotted to the Bureau from the National Security and Defense Fund to be used to constructing and equipping “war-emergency” laboratories. Work in these new labs included metallurgical research, gage work and military equipment research and development. The funds were used to construct additional facilities for the ever-expanding Bureau and also to hire world-class scientists whose salaries would have been unaffordable otherwise.
With the demand for troops, the Bureau also hired almost 100 women to fill the clerical and assistant positions vacated by the military drafts, though they continued to be excluded from the higher-level positions. One of the women hired at that time, Johanna Busse, would later rise to be chief of the thermometry section for 20 years. “The first woman with a doctoral degree in physics to work at the Bureau arrived in 1918, to assist in the preparation of a radio handbook for the Signal Corps. A second joined the colorimetry section a year later.”
Aside from the staffing issues, the Bureau adapted well to military research. Whereas before the war, much of the Bureau’s work was geared toward industry, it was relatively easy to transition to wartime research by viewing the military as simply another type of industry. Dr. Stratton, before Congress, could justify how most of the research the Bureau was already engaged in could be used in military applications and was thus able to secure continuing appropriations as well as funds for new projects. Each division of the Bureau was able to take on military research functions within their specialty with ease. As one report indicated, food and medicine were the only two facets of the war effort in which the Bureau was not involved.
The study of metals and their properties was the Bureau’s biggest project of the wartime effort as need arose for weaponry, tools, airplanes, etc. Whether for ease of production, scarcity of materials, or improved properties (such as lighter weight or thin construction), many new steel alloys were used during wartime and they were sent by their manufacturers to the Bureau for testing of their exact composition and qualities. In the process, the Bureau developed standard tests for these metals. They were also involved in the search for substitutes for metals that had become scarce as a result of the war, like platinum.
Aside from metals, a number of other materials were also in short supply at the time. The Bureau assisted in identifying acceptable or unacceptable substitutes for leather (primarily in shoes), and paper. Bureau research also supported the substitution of a cotton fabric for linen that was used to cover airplane wings, as linen was also scarce. Wool was also mostly imported at the time, so research was conducted to find substitutes for military uniforms and blankets.
One result of the scarcities and substitutions of materials was that industries were forced to standardize their products to a degree that had not been seen before. The government instituted the Conservation Division to oversee the efficiency of production of various items with the result that variety was reduced and standardization increased. For example, it was during this time that standard clothing sizes came to the fore. In the name of conserving fabric, men’s coats were shortened and outside pockets eliminated. With the scarcity of silk and wool, women’s fashion changed dramatically as well. “Newsprint for papers and magazines was cut as much as 20 percent. Colors of typewriter ribbons shrank from 150 to 5 and were sold in heavy paper instead of tinfoil and tin boxes. Buggy wheels were reduced from 232 sizes and varieties to 4, plows from 326 to 76 sizes and styles, and automobile tires from 287 types to 9.”
The Bureau was also highly involved in the development of aircraft for the war, including parts, metals for construction, instrumentation to be used in flight, fuels and lubricants. The Bureau also development a wind tunnel to further exploration into the physics of aviation.
Post-World War I Research
After the war was over, the Bureau realized that despite all of the testing it undertook for various Government departments, no real demand for standardization of products existed for the Government as a whole. For example, the Army and Navy would ask for the same item but with very different specifications. These specifications were developed independently by the requesting department with no regard as to the practicality or feasibility of production. Although in many cases, the standardization requested by departments was impractical or impossible, the nation’s readiness to accept standards and standardized products primed it for the age of mass production.
Prior to the war, there was little interest in this country in the manufacture of quality optical glass. Glass used in scientific instruments, like telescopes or microscopes, was imported, mostly from Germany. Research premises and tools were ordered in 1914 to determine a production process for American-made optical glass. Progress was slow owing to a lack of precision glass grinders, but the need was great as the war required troops to have binoculars, periscopes and gun sights. With optical glass, as with many wartime projects, the experiments were hastily prepared and most of the developments came too late for practical application before the war was over.
Developments also continued in radio, with the war showing Americans that Europe had far more advanced radio technology. Visiting scientists from France left the Bureau with various radio instruments they used in 1917. The most important technology to be found in these instruments was the electron tube, also called the vacuum tube amplifier, which had been invented in America but not put into practical use due to issues regarding patent law. The French, meanwhile, were using it in all of their radios, wire telephony and radio telephones. When the legal issues were finally resolved in 1917, work began immediately to resolve this country’s radio problems, including training technicians, establishing a transatlantic radio system, development of radios for use on the battlefield, equipment to communicate with submerged submarines and more.
Research began in earnest to explore the possible uses of the electron tube, resulting in reliable long-distance wire telephony and speech communication between ground stations and airplanes. The vacuum tube could be used to locate transmitting stations, which was useful for identifying enemy positions during the war and for locating stations in violation of transmitting laws. It was also used to guide planes and ships through fog. Furthermore, as an amplifier, it allowed for smaller antennas and extended radio range.
Following a conference of university representatives at the end of 1917 regarding radio communications, the Bureau issued Circular 74, “Radio instruments and measurements” which was issued to radio instructors in the armed forces and universities as a reference book. For more than 20 years, it was the authoritative text for radio engineers. Following the publication of Circular 74, the Signal Corps requested a beginner’s textbook on radio for enlisted men. “The Principles Underlying Radio Communication” appeared 3 months later and was the result of collaboration between the Bureau and 6 college faculty members and came to be widely used as a standard textbook by both the military and the academic world.
The war also introduced the country to the concept of interchangeable parts manufactured by different companies in different parts of the country. Largely a result of the production of weaponry and ammunition, the production of interchangeable parts required a phenomenal degree of precision in measurements and manufacturing which was achieved by the use of an unprecedented number of gages. The Bureau saw unprecedented demand for gage production, development and calibration. The domestic production of precision gage blocks (only available by import from Sweden prior to 1918) was essential to the manufacture of interchangeable parts. With funding from the Ordnance Department, the Bureau produced 50 sets of 81 blocks ranging from 0.05 inch to 4 inches. Also of utmost importance was the work of the National Screw Thread Commission, which sought to standardize, and thus render interchangeable, all machine-made threaded products.
The Bureau was introduced to countless inventions during the course of the war, including the rocket. Rocket technology was nothing new, but incorporation of new technologies made the rocket promising as a weapon. The Bureau developed test rockets with ranges 7 miles and 120 miles. Various other weapons were developed around rocket technology, but the wartime shortage of research scientists meant that none of these ideas were realized during World War I. The Bureau was also introduced to the automatic rifle, another invention that wouldn’t find its footing until World War II.
Security at the Bureau of Standards
Despite all of the war-related research conducted at the Bureau, security was relatively lax. There was always a guard on duty, but most projects were not classified and security clearances were not required for the staff. In fact, the atmosphere was so relaxed that one day President Wilson, his wife and Secretary Redfield made an unscheduled Sunday visit to the Bureau to see the all-metal airplane being tested and although the building where it was kept was locked, they found an open window and all three climbed through to have a look. Another anecdote illustrates the ability of the Bureau to have fun: “An avid reader of detective and mystery novels, the President one morning sent a messenger to the Bureau with an envelope bearing his seal. He had read the night before that such a letter could be opened and resealed without any sign of tampering. Could the Bureau do it too? A day later the President had his sealed letter back, apparently intact. Inside was a note and the lead disks from which the fraudulent seal replacing his seal had been made overnight.”
Budget Adjustments for the Bureau
With the somewhat abrupt end to the war, the Secretary of Commerce expected the Bureau to cease some activities and reduce staff that had been added for wartime research, but the Bureau reply was that they expected no reduction in work or staff and anticipated an increase in requests from the military, who were now aware of the need for more modern weaponry and technology and aware that the midst of a war was not the time to be addressing such concerns. As Congress greatly reduced appropriated funds for military research to the Bureau, the continuation of some projects had to be funded instead by the Army, Navy, etc. or the Agency to be served by the research. A precedent was thus set for transferring research funds within the budgets of other departments to the Bureau who would be carrying out the research. In later years, it would prove easier to obtain funding in this manner than asking Congress for direct appropriations.
After the war, Congress did award a large increase to the Bureau’s budget for industrial research, as the war had proven the connection between science and industry that was sure to prevail into the future. Americans were also made aware that the most important developments in physics and chemistry were coming from Europe at the time and they needed more research funding in order to remain competitive. Just as the switch from prewar investigations to military concerns had happened rather seamlessly, each department having wartime applications, the postwar argument was that practically all of their military work had industrial value and should thus continue. There was also a postwar interest in continuing the research to produce domestically the materials, instruments and other items previously imported from Europe that fed into the ongoing work of the Bureau.
Without wartime funding, the Bureau once again faced a staffing problem caused by the fact that private industry saw the need for trained investigators and could offer better salaries than the Bureau could, and as a result lost over 78% of its appointed staff members within 7 months of the armistice. For most positions, the Bureau paid less than a living wage to its employees. Recent college graduates might receive a decent entrance salary at the Bureau, but with industry competing for them too, it was not enough to offset the exodus.
The answer at the time to the staffing problem was to convince industry to send researchers on their payroll to the Bureau to conduct the research necessary. These “research associates” would then make their work available to the public, rather than doing secret experiments for the company that employed them. Having begun in 1919, this method yielded 61 research associates paid by 36 organizations by 1925.
In the postwar atmosphere of the country, the Government was accused of being too big and too inefficient. Answering this charge, the Bureau undertook studies on the cost and efficiency of the Federal Government itself. The resulting studies argued that, given the climate, more Government was actually in the public’s best interest to combat problems such as profiteering and inflation. According to the reports, the public needed to be better educated regarding Government spending. Almost 70% of federal income was used for paying interest on the national debt (incurred mostly through past wars) and only 3.2% was used to actually run the Government. The inefficiencies identified in the Bureau report, were the result of insufficient spending on salaries, meaning that Government posts did not attract or retain qualified personnel.
Changes in Leadership
In 1921 and 1922, the Bureau went through some profound staffing changes, with 3 of its division chiefs dying in a span of 10 months. All 3 had been with the Bureau from the beginning, and its head, Dr. Stratton, had a bond with them that was not present with more recently acquired staff. Between losing his closest staff members and the fact that he was underpaid (he would have made at least 4 times more in the private sector), Stratton’s days at the Bureau were also numbered. The Bureau’s strongest champion, the man who had shaped it since its founding and seen it grow to more than 60 times its original size, left his position to assume the presidency at MIT beginning on January 1, 1923.
Secretary Hoover called attention in his press release on Stratton’s resignation to the fact the Government salaries were not competitive enough to keep qualified scientific men in Government positions. Hoover also named Stratton to the Bureau’s Visiting Committee, which meant that his influence was still felt there after his departure. Stratton also continued to be available for consulting with his successor Dr. Burgess, and during his tenure at MIT, he oversaw a reorganization that in many ways resembled the organization of the Bureau.
After rather lengthy debate, George Burgess, chief of the metallurgy division, was named successor to Stratton. Like his predecessor, Burgess would champion the link between the scientific study of the Bureau and industry, but unlike Stratton, Burgess was less involved in the day-to-day functions of the Bureau across the spectrum. He delegated authority, in contrast to Stratton’s autocratic nature, but he was accessible to any who sought his guidance. Under Burgess, the Bureau’s growth slowed as he was content to continue with work begun under Stratton, but let the dust settle for a while before taking on too many new tasks.
Some of the most important work conducted during the 1920’s was the Bureau’s continued work on establishing constants for different substances. The Bureau was especially concerned with temperature tables for different materials and greatly improved the data available for things like boiling and freezing points. They also collaborated on a new International Practical Temperature Scale. During this time the Bureau also investigated, in far greater detail than anyone ever had before, the specific characteristics of chemical elements, both alone and in combination with other elements by using spectroscopic test methods.
The Bureau’s involvement in the field of atomic physics began with a guest researcher from the University of Minnesota who introduced the concept of spectral analysis of metal vapor atoms. What began as an unfunded research hobby of two researchers in the optics division became the Bureau’s atomic physics section in 1922. The majority of the Bureau, however, continued to be consumed with industrial research.
Following the war, the country experienced a period of depression with the slowing down of industry. At the time, Herbert Hoover, who strongly supported the Bureau’s work and saw its value in restoring the economy, was Secretary of Commerce. The war had produced a housing shortage so when it became apparent that new home construction would be instrumental to job creation and industry revival, Hoover tasked the Bureau with researching the standardization of building materials and reviewing building codes. Hoover also established within the Bureau a division of simplified practice, whose purpose was to eliminate waste in industry by encouraging more conservative use of materials and more streamlined practices.
Bureau publications during the course of this housing stimulus included “Recommended minimum requirements for small dwelling construction,” “How to own your home,” and primers on plumbing, zoning, building codes and city planning. Bureau investigations also concluded that it wasn’t really necessary to have the customary winter slow-down in construction. The housing construction program lasted 8 years, from 1921-1929 and averaged 750,000 homes annually, which dramatically exceeded the need at the program’s inception. With a surplus of homes available, the Bureau’s building division saw staffing cuts from 36 to 2 by the time the Great Depression was in full force in 1933.
Crusade for Standardization
A report by the Federated American Engineering Societies in the 1920s had concluded that between 25-50% of production costs could be eliminated by eliminating waste (including, in some cases, wasteful labor practices). Hoover’s aims at achieving waste reduction affected the Bureau directly on two fronts: 1) that material waste reduction would be achieved by setting standards of quality, simplifying grades and reducing unnecessary variety; and 2) that labor waste reduction would be achieved by scientific development of better processes and methods and invention of labor-saving devices.
“The crusade for standardization” became a phrase used to express the objectives of standardizing materials and business practices, reducing extraneous variety, and producing quality specifications. Independent of, but in close connection with the Bureau, the actual authority regarding industry standards was the American Engineering Standards Committee or AESC (later renamed the American Standards Association). The year 1927 saw the first publication of the Bureau’s “Standards Yearbook” which provided fundamental information on standardization which by then, it claimed, affected “every phase of design, production, and utilization.” Industrialized countries around the world underwent their own “crusades for standardization” during the same period, as the phenomenon was not contained to the US, though with the distinction that in the US it was driven largely by industry as a matter of increasing profit, whereas abroad it was more likely to be a government initiative.
As we have seen earlier, establishing quality standards for government purchasing was one of the Bureau’s former tasks, though for a long time, each department or agency had its own purchasing department and its own quality standards. With the establishment in 1921 of the Bureau of the Budget came the creation of the Federal Specifications Board which bound all Federal purchasing to Bureau quality standards.
The general procedure, then, was for the Bureau to conduct research and recommend a standard, which was then conveyed to the AESC. From there, the draft of the Federal specification was disseminated to industry representatives who, in turn, provided feedback until a standard was approved. In this way, the Bureau prepared 72 specifications between 1921 and 1924 and 150 new specifications between 1925 and 1928.
Together with other concerned parties, the Bureau published the “National directory of commodity specifications” in 1925, including 27,000 specifications for 6,650 commodities, which Secretary Hoover envisioned as a “Buyers’ Bible” to support industrial and Federal purchasing.
Of the various branches of the standardization initiative, the general public seemed most interested in the topic of simplification because it was easy to understand and often came with staggering statistics. For example, a Bureau report in 1921 showed excessive variety in style and material when there was no real demand for such variety and consumers would have been content with a more standardized selection. The same report found that this issue alone represented an annual 30% loss of American energy.
As its first two recommendations, the Bureau’s division of simplified practice reduced the available sizes of paving bricks from 66 to 7 and beds from 20+ varieties to 4 widths and one arbitrary length (we see the vestiges of this in our current twin/full/queen/king sizes). In cooperation with the Bureau, savings over $293 million were estimated in nine key industries within 5 years. A study in 1926 found compliance rates to the new standards to be at 79.5%, exceeding expectations, which had assumed that manufacturers and consumers would try to hold on to eliminated sizes/styles of product. The program continued to enjoy much success with manufacturers reporting savings and benefits seen in numerous facets of their operations. As such, Hoover created within the Bureau the division of trade standards to consolidate activities related to standards and publish specifications with industry-wide application.
While manufacturers accepted the reduction in variety and standardization of their products relatively readily, as they saw the results on their balance sheets, consumers continued to want that additional variety in some products. In an ironic example, the heads of the simplified practice division at Commerce requested typewriters for their division that were not of the manufacturer and type style used throughout the rest of the organization. Their request was denied on those grounds but they insisted until their purchase was approved, illustrating that limited variety does not always suit all needs or wants of the end user. As the country rebounded from the post-war depression, both industry and consumer became less compliant with Government simplification recommendations until the program was drastically cut, though not abandoned, when the Great Depression hit.
Reducing Waste and Improving Quality in Various Industries
Picking up the thread of reducing waste and wasteful practice in industry, the Bureau in the 1920s tackled issues of efficiency in a range of products and industries, particularly the growing auto industry, with studies on auto engines, tires and oils, and public utilities with studies on improving gas appliances and minimizing dielectric loss. Testing on construction materials, crucial to Hoover’s home building initiative, concluded that often more of a building material was used than was structurally necessary, when less material would produce a structurally sound building. Other projects of the time included everything from sound-proofing techniques to fire-proofing to recovery of waste sugar.
Bureau investigations during the 1920’s on gas and gas appliances proved to have a significant impact on public health and safety. On its own initiative and using funds granted by Congress in 1915 for investigation of public utility standards, the Bureau began a new investigation of the gas industry prompted by rising gas prices and a belief that that the natural gas feeding half of the cities and towns in the country was in short supply. The Bureau’s aim at the outset of the investigation was to promote conservation of this supposedly dwindling resource.
Testing concluded that the greatest source of natural gas waste was domestic appliances, prompting the Bureau’s publication “How to get better service with less natural gas in domestic gas appliances.” In the course of the overall gas project, the Bureau also tested a number of “gas-saving” devices that promised to lower consumers’ gas bills when used in conjunction with their gas appliances. These products actually did no such thing and in many cases their use created additional safety dangers. The true culprits were the poor design and faulty installation of appliances, though Bureau recommendations for design changes to stoves, water heaters and room heaters were met with backlash from the industry or were simply rejected.
The winter of 1922-1923 saw an increase across the country in deaths from gas poisoning. The Bureau worked together with municipal health departments to compile data on fatalities attributed to carbon monoxide, which, in turn, shed light on the gas industry’s dubious practice of attributing all gas-related fatalities to suicide by carbon monoxide poisoning (even in cities supplied by natural gas which did not contain carbon monoxide). A subsequent investigation by the Bureau in conjunction with Baltimore’s Consolidated Gas & Electric Co. and public health officials reaffirmed gas appliances to be the primary source. Upon publication of the findings, the president of the American Gas Association, enraged, “demanded that further publication be withheld.” The data, however, was undeniable and the Association ended up installing a research associate group at the Bureau. They later hired a Bureau gas engineer and set up their own laboratories and quickly revamped the industry. Within a couple of years, gas poisoning deaths in Baltimore had all but been eliminated. So this shows but one example of how the Bureau’s work could literally be a matter of life or death for the public.
By the mid-1920s the Bureau was reporting that domestic production of scientific and industrial instrumentation had increased to 80% as opposed to 15% before the war. They also reported much greater cooperation from industry, especially large corporations, than they had received at the Bureau’s inception. A widespread concern of the time affecting many different industries and interests was the standardization of color.
The colorimetry section was formally established within the optics division of the Bureau in 1915, but Bureau interest in the topic went back to 1912 when they were called on to aid oil, butter and margarine makers with color grading their products. When the section was established, they had requests regarding color issues as they related to glass, headlights, paper, sugar and many others. At the time, two color scales were in use, but both had limited application. The unique problem with measuring color is that it is, to a degree, subjective. That is, color is in the eye of the beholder. Recognizing this psychological element to the way humans perceive color, the Bureau studied 150 subjects to establish a data curve. This curve was accepted as the standard by the International Commission for Illumination in 1924. Further years of work eventually resulted in the Bureau’s dictionary of colors and color names.
Next, the Bureau’s began its investigation of dental amalgams. In 1917, the Surgeon General of the Army approach the Bureau with this problem because of the widespread issue he faced of dealing with dental issues. Insiders from the dental industry worked with the Bureau, which eventually concluded that half or more of dental materials were unsatisfactory. Although dentists, manufacturers or dental materials and dental testing labs cooperated with the Bureau, the government, in the form of the Commerce Department, suppressed the unsatisfactory findings for fear of creating a loss of public confidence. The Bureau helped identify the best adhesives, filling materials and more for use in the dental industry and within about 10 years, unacceptable materials had dropped from 50% to 10%.
Bureau efforts during the 1920s continued to span a variety of industries but the construction industry was probably the source of the most investigations. From elevator safety to fire resistance, almost 100 projects relating to construction were taking place in all divisions at the Bureau – electrical, heat, chemistry, metallurgy and more.
As the Bureau became involved in the manufacture of optical glass for binoculars, scientific instrumentation and the like, private industry showed little interest in taking over this manufacturing process, so the Bureau continued its manufacture of glass, mostly for the military. In 1924, the Bureau attempted to cast a 69.5 inch disk for a telescope. At the time, only the country only had two other large glass plants, both with equipment from Europe, whose technology was a trade secret. The Bureau had to draw on their knowledge and experiment. The first four attempts all cracked during cooling, but the fifth attempt, poured in 1927. After some seven months of controlled cooling, the disk, which weighed 3,800 pounds, was declared to be a success.
In addition to the large disk, the optical glass section’s other great triumph was the creation of the Bureau’s first standard of planeness created in 1926. It was used as a standard of straightness and planeness whose accuracy measured to five-millionths of an inch. It was also used to produce standard angles and to calibrate instruments for measuring curvature. The glass industry of the time also saw major development through the manufactures of automobile windshields and windows.
The automobile industry continued to expand by leaps and bounds, despite warnings about the scarcity of petroleum resources, which were estimated to be exhausted in 10 years. The need thus arose to ensure the quality of gasoline on the market, which, through practices meant to conserve it, would often lead to a substandard product for the consumer. The Bureau recognized that quality gasoline would make a car’s engine perform more efficiently, thus reducing consumption.
A whole new area of investigation was born at the Bureau, which published papers on efficiency characteristics of different fuels and oils for use in cars. The Bureau tested various types of antifreeze, but didn’t endorse any as none worked better than alcohol and water. Studies were also conducted on fuel-air rations and engine temperatures, among other things. An investigation concerning brakes for the Army Motor Transportation Corp eventually lead to research on stopping distances and reaction times of drivers. This data collected by the Bureau was used in driver manuals for years after. Some other Bureau studies that grew out of the auto industry were investigations regarding rubber (for tires) and storage batteries used in electric vehicles.
While the auto industry eventually assumed responsibility for much of its own research and development, the aviation industry was slower to become self-sufficient. Several government committees and departments were involved in regulation of the aviation industry, and all used the Bureau to conduct research on areas like engines, fuel economy, ignition, instrumentation and aerodynamics. The industry, or at least the military, was not ready in the 1920s, however, to take a chance on new technologies explored by the Bureau including helicopters and jet propulsion. The military push at the time was for “lighter-than-air” craft such as dirigibles. The Bureau supported the military by providing instrumentation for these craft, like navigation equipment, and conducting durability tests on the construction materials used. When dirigibles proved not to be a viable option for safe air travel, the focus did switch to planes, and with the promise of civilian commercial flight, the Bureau increased work on the radios necessary for ground-to-air communication and the beacons that would guide planes in flight.
The Growth of Radio in the US
In addition to the other industries exploding at the time, radio saw huge development in the 1920s. With the end of the patent wars between major manufacturers, radio broadcasting began. Reaching an estimated 7,000 privately owned radio sets in 1921, radio grew during the decade to reach 10 million commercially-produced and privately-owned sets by 1928. The Bureau, for its part, produced circulars instructing consumers on how to build their own radios with different instructions depending on the desired range of reception. The rapid growth of the industry soon had the Bureau calling for standardization of equipment and service.
With new radio stations popping up across the country, the government eventually found it necessary to regulate the airwaves. Technical advisors from the Bureau were present at all early radio conferences with Bureau researchers Dr. J. Howard Dellinger and Dr. Charles B. Jolliffe eventually becoming the first and second chief engineers of the Federal Radio Commission.
Of the early obstacles to commercial radio, the Bureau was most concerned with improving reception for the listener by devising ways in which the stations could use more precise waves to reduce interference from irregular wave widths. The Bureau developed a variety of new instruments and tools (wavemeters, wavemeter scales, etc.) to aid stations and government regulators in making sure stations stayed on their assigned frequency. Also among Bureau responsibilities was the testing of the frequency standards for broadcasting stations adopted by the FRC in 1927. Later investigations by the Bureau, in cooperation with the radio industry and academia identified that fading could be attributed to irregular absorption of radio waves in the ionosphere. Weather was found not to be a factor, but day and night produced consistent variations in reception. This finding lead to research into shortwave transmission, which was less susceptible to interference.
Amidst all the work on commercial radio, radio compasses were also improved for the Navy and other ships. High frequency radiotelephones became the preferred navigational tool for the Coast Guard and the Bureau of Navigation. Useful as the radio compass was, it was deemed inadequate for passenger flights, leading to the development in 1929 of the first visual-type radiobeacon system, which allowed the pilot to know his aircraft’s approximate location at all times. The following year, a system was developed to allow for blind flying and blind landing where the pilot’s only frame of reference for his position came from indicators on his instrument panel showing his position as determined by signals from directional beacons. Then, in 1933, a system was developed to allow nongovernment craft lacking the equipment to use the beacon system to navigate based on the radio waves of broadcasting stations.
Tension Between the Bureau and the American Standards Association
With industrial growth and standardization efforts in the 1920s, the Bureau became much more visible to the American public, with one result being that the Bureau was flooded with mail and requests ranging from the legitimate to the insane (such as a request for a pamphlet on what the average American should be or for a standard for what well-dressed person should wear and even advice on protection against radioactive dictagraphs that controlled people hypnotically). One of the most numerous requests was for the invention of a device to locate buried treasure. The Bureau created a form letter advising people to just dig by way of response to those requests.
The Bureau’s increased visibility also brought increased criticism. Opponents to the standardization crusade questioned what, if any, was the benefit to the general homeowner. The cost savings to industry were clear, but at the level of the individual consumer, such savings were not apparent. Part of the disconnect was that the Bureau did not explicitly distinguish between the “organized consumer” like the government or trade associations and the individual consumer, despite its genuine concern for the individual consumer and insistence that all of its research benefited the consumer by improving the quality of products offered to him.
So, while industry resent the government’s oversight into their products and practices by means of the Bureau and while consumers cried for still more oversight, the Great Depression hit, reducing Bureau resources that left both sides feeling even more discontent.
Among those to voice concerns about where the Bureau’s authority began or ended was the AESC (American Engineering Standards Committee) which had been created under the eye of the Bureau to deal specifically with industry standardization. When the Bureau then established a “trade standards division” in 1927 to unify the efforts of the Bureau and the AESC, the AESC bristled. Under the direction of a former Bureau member, the AESC became the American Standards Association (ASA) and formally requested that the Bureau cease commercial standardization activities. A rift between the two organizations ensued.
As the 1920s came to a close, the tension between the Bureau and the American Standards Association (ASA) continued, with both organizations claiming that the other was impeding their ability to effectively function. The ASA wasn’t the only source of animosity towards the Bureau. During the 1920s, newspapers including the Washington Post pointed to the Bureau as a prime example of wasteful government spending. From time to time, action was taken to limit Bureau authority (as in the case where the Bureau was informed that it was not to make optical glass for the Navy and would receive no further funding to do so), but the Bureau consistently proved the necessity of each project that came under fire (in the Navy example, when the Bureau proved that no other source was available to produce optical glass to meet Navy standards, the funding that was to be withheld was release and operations resumed).
Still another area of attack which developed during the 1920s-30s was the line of argument that the Bureau, while funded with taxpayer dollars, principally benefitted the government and that results of Bureau investigations should be made public so as to benefit the consumer directly. Of course, the reason that was not done was to protect manufacturers from commercial injustice, so the Bureau faced a double-edged sword on that point. Critics of the Bureau found plenty of other points to contend as well, including the system of using research associates employed by industry and not by the Bureau itself and argument that the Bureau directly competed with private research organizations.
In response to this series of criticisms, the Bureau itself petitioned the Department of Justice for a review of its organic act and subsequent congressional acts to determine if, in fact, the Bureau was conducting research beyond its limitations. The DoJ found no impropriety on the Bureau’s part. Later, Congress conducted a review of government interference in industry. Here, too, the Bureau was found to be least a fault among government agencies engaged in industry regulation. Actually, the report indicated that without government intervention during WWI, industry would not, on its own, have been able to meet the production demands of the time, but did conclude (without mentioning the Bureau of Standards by name) that perhaps funding limitations would be prudent.
The Bureau During the Great Depression
Following the stock market crash of 1929 and the absorption into the government fold of many utilities and public works, the Bureau operated fairly normally. In fact, there was no formal acknowledgment of the Depression from the Bureau until a note of “reduced industrial activities” appeared in 1931, with an indication that the Bureau was taking measures to operate economically. Nevertheless, Dr. Burgess’ annual report of 1931 included the largest number of projects ever, 525. Funding for the Bureau had increased in 1931 also, allowing for salary increases, new laboratories and radio stations and land to expand Bureau facilities. Bureau administration continued to justify its large staff and fiscal requirements by vowing to focus its efforts on those projects that would help lift the country’s economy and relieve unemployment.
1932 told a dramatically different story. Funding was cut by 20%, but Dr. Burgess died before seeing the effects of the Depression on his agency. His successor, following much debate on the merits of promoting from within versus hiring an outsider, was Dr. Lyman Briggs, formerly assistant director for research and testing. Briggs was known for his calm demeanor and even temper, which he would need during the Depression and subsequent war years. A passionate baseball fan, one of Briggs last experiments in his life, conducted after he left directorship of the Bureau, was to scientifically test the degree to which a baseball could be made to curve in the 60 feet from pitcher to batter. Unfortunately, his years as Director were not as much fun as that experiment.
During the Depression years, his chief objective was to keep as much of his staff as possible and to convince Congress and the Roosevelt administration of the Bureau’s need to fund projects that could not directly be tied to alleviating the Depression. Despite proposals to eliminate the Bureau altogether, salary cut after salary cut, and the threat of dispersal when Roosevelt endeavored to reorganize government departments, the Bureau lived on through investigations by its own Visiting Committee, the Business Advisory and Planning Council and the President’s Science Advisory Board.
Now, the Bureau was facing three simultaneous investigations into its functions and budget. All three investigations resulted in the conclusion that it was necessary for the Bureau to continue performing essential testing whether specifically noted in its organic act or not. The investigations also pointed out that the Bureau had been hit disproportionately hard by funding cuts and staff reductions during the Depression, although they differed in their recommendations of how the Bureau should move forward. While no official change was made to formalize Bureau authority to perform testing deemed by some to be outside its scope, tacit approval was given by the new appropriations of 1935, which replaced 29 appropriations items with one act divided into four general funds, one of which included a provision for the Bureau’s continued involvement with the ASA and work on standards for commerce.
As the Depression dragged on through the 1930s, Dr. Briggs repeatedly contested that new inventions would stimulate industry, the consumer and the economy. One stimulus strategy employed at the time was the idea of transforming the nation from a production-based economy to a consumption-based economy, or ushering in “consumerism.” The National Recovery Administration, set up by the Roosevelt administration in 1933, would be advised by an Industrial Board, a Labor Advisory Board and a Consumers’ Advisory Board to ensure maximum benefit to all parties from new legislation concerning issues like minimum wage, work hours and price regulation to the end of stimulation consumption.
The task of the Consumers’ Advisory Board was to promote use of specifications and labeling in consumer products through NRA code, but some believe agencies like the ASA and the Bureau of Standards incapable of making such recommendations because of their perceived propensity to favor industry above the consumer. Despite this concern, there were no reasonable grounds for setting up an independent laboratory for the task, so over the NRA’s 2-year life, the Bureau reviewed almost 500 codes for fair competition involving consumer standards.
Over the course of the late 1920’s to late 1930’s a number of agencies, publications and laboratories appeared dedicated to consumer education, but they lacked the organization to form a unified national force. The Bureau, for its part, had difficulties working with these consumer groups because their organic act legally oriented their efforts to industry. Nevertheless, the Bureau recognized the benefit of performing consumer testing within a single institution under the Federal Government but thought the creation of a consumer testing agency unlikely as Congressional funding would probably not be approved. The Bureau cooperated with the consumer movement by advising consumer laboratories on their test instruments and equipment, developing new testing equipment and issuing publications geared toward the individual consumer. One such publication was entitled “Services of the National Bureau of Standards to the Consumer,” which explained how the Bureau’s efforts benefitted the individual.
Even though it was a challenging period, the Depression created lulls in committee assignments to the Bureau and travel, as well as drop in supervisory duties which created more time for actual research. The Bureau was forced to make staffing cuts and could not hire qualified scientists, but their funding did provide for “clerks” and “draftsmen.” It was also during this time that Dr. Brigg won his battle to add the word “National” back to the Bureau’s name after 30 years of being the “Bureau of Standards.”
Finally, in 1935, the Bureau could document an increase in requests from industry for data. This coincided with increased building at the state and federal levels which brought an increase in government requests for tests and calibrations (as well as a modest increase in funding, sufficient to rehire former staffers). In 1938, Congress approved construction of a new electrical testing laboratory to replace the obsolete one built 25 years earlier when voltage ranges were much lower than those being produced in the late ‘30s, further evidencing the improving economy. Thanks in large part to new dam-building projects across the country, the opening of new branch laboratories also increased during the late ‘30s.
Efforts to stimulate the economy through low-cost housing also led to Bureau funding for research into structural and fire-resistant properties of construction materials to be used for housing. This program and its funding were cut from New Deal sponsorship as WWII approached, but the work continuing at the urging of the building industry. After a hiatus during the war, building technology became its own division within the Bureau in 1950.
Also during the 1930s, the Bureau completed research relating to the preservation of paper records. The work, funded by the Carnegie Foundation, tested the effects of such forces as light, heat and humidity on storage of paper and books. Sulfur dioxide was determined to be the greatest enemy of paper storage. The work led, in turn, to studies on the preservation of all types of media and to the Bureau’s involvement in the preservation of the Declaration of Independence and the Constitution at the National Archives.
Another interesting line of study at the time related to X-ray dosages and ultraviolet radiation. Although both technologies were becoming quite widely used by medical professionals, they did not really understand the thresholds of safe and unsafe exposure, particularly to the equipment operators as opposed to the patients. At the urging of the president of the Radiological Society of North America, Congress provided funding at the Bureau began to research the issue. Physicist Lauriston Taylor, who had been working on X-rays and electronics at Cornell was brought on to Bureau staff to lead the work.
Taylor’s first order of business was to construct new equipment for the testing, which he did from parts of other equipment on hand at the Bureau. In 1928, he attended the Second International Congress of Radiology and became the first Chairman of the National Committee on Radiation Protection and Measurements. Taylor published research in 1929 showing that X-ray dosages could be quantitatively measured and in 1931 he published guides for safety shielding of operating rooms, patients and operators. Similar publications for radium, at the hand of Dr. Leon Custiss, followed in 1934.
Paints, made from compounds including radium, were developed to have luminous properties for applications on instrument panels for the military during WWI and also on watch faces. Little was known about the effects of the radium paint at the time. It was later determined that the amount used for a watch face was fine, but the problem was the factory application of the paint to the watch during production. Being wartime, mostly girls worked in the factories and the put their paintbrush tips in their mouths to draw them to a point, thereby ingesting the paint. Hundreds of these girls died of what was later diagnosed as radium poisoning. In 1932, the American Medical Association discontinued all internal administration of radium as a remedy. The Bureau’s research on the topic was found in the 1932 handbook on radium protection and in 1941 it had a handbook of its own.
Also during the 1930s, work advanced in spectroanalysis with new and accurate measurements of the atomic emission spectra of chemical elements, rare gases, and rare metals. An index was published by the American Society for Testing Materials that listed almost 1,000 papers on the subject written during the preceding two decades. Dr. Briggs also proposed that the Bureau sponsor a central agency for computing fundamental tables for applied mathematics. With basically no equipment provided, the project began in New York City with hundreds of workers doing calculations by hand. The first order of business? To prepare the 16-place values of natural logarithms, the 15-place values of probability functions, and the 10-place values of Bessel functions of complex arguments. Within a decade, equipment existed to compute in minutes what 400 individuals with pencils did in months, but the Mathematical Tables Project was widely and gratefully recognized at the time.
With the establishment of the Mathematical Tables Project, which, by 1943, had produced 27 book-length tables as well as many shorter ones, the thirties also gave rise to an undertaking to identify and quantify the physical constants of pure substances, especially of industrially important organic compounds. Importing a method devised by a scientist at the Polytechnic Institute of Warsaw, Bureau chemists researched a number of substances by determining their vapor pressure, boiling point and more.
Thus, although the Great Depression brought with it reductions in staff and funding, as well as other hardships, the reduced bureaucracy of the time allowed the Bureau staff who remained to focus their energies on some much-needed fundamental research that would serve as the building blocks for years to come.
In September 1933, two Bureau researchers, Burt Carroll and Donald Hubbard, were awarded medals by the Société Française de Photographie et de Cinématographie in recognition of their contributions to the world of photo-sensitive emulsions. The Bureau’s involvement in this field began in 1921 with the need for emulsions sensitive to infrared spectra for which commercially available film was unsuited. With German equipment installed in the basement of the Bureau’s chemistry building, Carroll and Hubbard set to work on creating a better film. For 7 years, their efforts were largely futile with sometimes over 400 batches of emulsion made in a single year. By 1933, however, the two were publishing their 17th report on the mechanism of photographic hypersensitivity. They were finally creating emulsions superior to commercial ones and in publishing their methods, they would threaten trade secrets of those commercial producers. Therefore, when budget cuts were made, the emulsion project was among the first to go as one of seven projects which the Visiting Committee specifically targeted (the others were heavy hydrogen research, dental cements and alloys, certain industrial concerns, internal combustion engines, production methods for levulose and the design of a telephoto astronomical objective).
In 1933, Congress made its biggest reduction in Bureau appropriations with a cut of 54 percent which affected over 100 projects. Particularly hard hit were the projects involving automotive engines (over 40 different projects), because of their unpopularity with the auto industry when, for example, one manufacturer’s engine was deemed by the Bureau to be superior to the others. Also due to budget concerns, the Bureau surrendered work on standardization and specifications to the American Standards Association. Amid backlash from the industrial community at the change, it was agreed that the Bureau would continue to cooperate with the ASA.
Around the same time, the Bureau and Dr. Briggs were embroiled in lawsuits regarding the issuance of patents to Bureau researchers. The practice under Dr. Stratton had been that patentable material would be patented in the name of the Government and would be for public use. This method was challenged in 1922 by two researchers of the radio section who developed a method by which radios could be operated by current rather than the traditional batteries. This innovation fell outside the area of their assigned field of research and as such, they filed three patents in their own names relating to the technology. In response, a formal policy regarding patents was devised and it explicitly stated that patents for inventions and discoveries of Bureau employees would be registered to the Government. The District Court of Delaware later decided in favor of Lowell and Dunmore because the invention was not part of their assigned work. An appeal to the US Circuit Court upheld the District Court’s decision as did a further appeal to the Supreme Court which was decided in 1933 in favor of the inventors.
While the funding cuts were bitterly made, Dr. Briggs did acknowledge that some programs had become entrenched, not because they were useful or truly merited ongoing research, but because all possible angles of research had not yet been completely exhausted. The reductions in staff and resources forced various projects, such as radio research, down to their absolute most important aspects.
Involvement in World War II
With much of the US in denial, a group of foreign-born scientists led by Niels Bohr foresaw the country’s eventual involvement in WWII. Bohr, for example, urged a moratorium on publication in the Allied countries of research related to nuclear fission. It was almost a year before the scientific community truly headed Bohr’s warnings. Dr. Briggs, from his position on the Advisory Committee on Uranium, began to prepare himself and his agency for the possibility of war. Briggs prepared for the Department of Commerce and list of services the Bureau was prepared to offer “in the event of war.” Among these: to test all materials to be purchased under the Strategic Materials Act, to increase its output of optical glass, to certify US materials sent abroad (especially instruments, gages, metals and cement), and more. Dr. Briggs also included with his memorandum a copy of “The War Work of the Bureau of Standards” which detailed the Bureau’s contributions during WWI.
The country as a whole was totally unprepared for a new war – the armed forces had outdated equipment (and that in short supply) while much of the nation was still facing the high unemployment and sluggish manufacturing of the Great Depression. The general mood of the country was against involvement in the war (as evidenced by the 1940 Democratic Party Platform) and thus mobilization to prepare for war was slow. In taking on projects related to wartime preparation, the Bureau was forced to begin classifying much of its research. As a result, the annual reports from the Bureau became restricted to only nonconfidential research. By 1942, so much of the material was classified that there was no point in printing the annual report at all. The sensitive nature of the work being done at the Bureau also led Dr. Briggs to close the laboratories to visitors, fence in the property and close Van Ness Street, which ran through the site. By the beginning of 1942, 90 percent of Bureau staff were dedicated to war research and Military Police patrolled the “prohibited zone” that was the Bureau grounds.
That the Bureau would be tasked with testing the strength and properties of material like metals used for weapons, airplanes and the like or with finding materials that could be substituted for those in short supply as a result of the war would seem obvious. There were also more obscure aspects of war to be considered, however. One interesting example is the Bureau’s participation in a “joint Army-Navy program to determine the characteristics of sky glow from artificial sources and the extent to which sky glow and shore lights might aid hostile ships offshore.” Among other priority Bureau projects during the early part of the war were research on petroleum conservation (because oil tankers were great targets for enemy submarines) and the production of synthetic rubber. Gas was rationed (to save the rubber in car tires more than to save gas), resulting in numerous citizen inventions intended to save gas being submitted to the Bureau for testing.
Thanks to the war, the Bureau’s staff would increase by more than 238 percent from 1939 to 1945, including over 200 members of the armed forces. Even more dramatic, funding increased from $3 million just prior to US entrance into the war to $13.5 million by 1944. To accommodate the huge demand for testing and the now huge staff, all of the Bureau’s conference and lecture rooms were converted to laboratories and 2nd and 3rd shifts were introduced to make maximum use of the space and equipment. The standard work week was also lengthened from 39 hours before the war to 44 hours.
The Bureau continued to be involved in the development of the atomic bomb by testing the purity of uranium and other elements. While many at the Bureau suspected that a weapon using uranium might be under development, the secrecy ran so deep and the security was so tight that even researchers working directly on the project sometimes failed to realize what the end-game might be, thinking instead that the uranium would be used for power plants to power planes or submarines.
Based on work out of Germany, France and Finland, and at the request of the US Weather Bureau, two researchers of the Bureau’s electrical division began an endeavor to devise a practical system of radiometeorography for the weather service. A similar request was made by the aerological division of the Navy’s Bureau of Aeronautics, this one being researched by a team from the radio laboratory. This second team’s offering seemed better suited to both requests, so the duo from the electrical division fitted the device they had developed with Geiger counters and began launching them 20+ miles up to gather cosmic ray data. Their findings would impact thinking on radiation and the effect of cosmic rays on radio communication as well as the study of atomic structure. Using data gathered from 18 launches of their device, Leon Curtiss and Allen Astin confirmed international reports proposing that the greater part of cosmic-ray phenomena was caused by secondary effects within the Earth’s atmosphere.
The team from the radio division, meanwhile, successfully devised a unit that transmitted continuous data on cloud height and thickness, temperature, pressure, humidity, and light intensity in the upper atmosphere. Dubbed the “radiosonde”, the device was effective at 15+ miles up and at distances up to 200 miles. By 1940, it completely changed the US weather and meteorological services with 35,000 units being built and launched each year.
During the 1930s and 1940s, the Bureau was party to nearly every expedition sponsored by the National Geographic Society, including visits to the polar regions and balloon flights 14 miles into the stratosphere. The Society and the Bureau co-sponsored an expedition to the USSR to observe and photograph the 1936 solar eclipse, capturing the first-ever natural color photographs of an eclipse using a 14-foot camera conceived and constructed at the Bureau. Both the camera and the Bureau would participate in several other solar eclipse expeditions around the globe over the next few years. Dr. Briggs even organized an eclipse expedition to Brazil in 1947 that comprised 76 researchers from the Bureau, armed forces and National Geographic Society.
Concurrent with this atmospheric research, huge breakthroughs were made across the world in the fields of physics and atomic research. The Bureau’s first studies in this vein were into atomic chemistry, not physics. The existence of isotopes (atoms of the same chemical element with different atomic weights) had been discovered, but researchers were having difficulty finding a heavy isotope of hydrogen using the existing technology. The Bureau stepped in to suggest use of its cryogenic lab to study liquid hydrogen where experiments confirmed the existence of the proposed heavy hydrogen isotope.
In a series of discoveries by American and European scientists, the existence of neutrons was confirmed and the first nuclear reactions were performed. Enrico Fermi experimented using uranium with an atomic weight of 238 and bombarding the atoms with neutrons to split the nucleus, but his results were inconclusive. Later experiments by others confirmed that the same isotope of uranium could be split and finally that it could be split into two nuclei of roughly equal size but producing enormous quantities of energy in the process. These findings were relayed to Albert Einstein by Niels Bohr, who also informed him that Hitler had control of the only known source uranium ore and had placed an embargo on it.
This news and its significance were conveyed to President Roosevelt, who immediately sought the advice of Dr. Briggs at the Bureau. Within a week, Dr. Briggs was chairman of the newly formed Advisory Committee on Uranium. The Committee’s task was to investigate uranium fission (faster than Nazi scientists could). Less than a month from Einstein’s initial letter to the President, the Committee issued a report indicating the distinct theoretical possibility of a chain reaction that would produce enough energy for an explosive weapon or to power a submarine.
As the Second World War began in Europe, and recognizing the potential implications of researching nuclear fission, Dr. Briggs hesitated as to what he and the Bureau should do next. Was this a line of research he and his organization would or should pursue? The Committee was absorbed, renamed and absorbed again into a series of other national defense programs created as Nazi Germany continued its European conquests, before finally becoming inactive under the umbrella of the Manhattan District division of the Army Corps of Engineers in 1942.
The Bureau After the War
Dr. Briggs proceeded slowly and cautiously when it came to the atomic issue, but one week before the attack on Pearl Harbor, there was an official recommendation made to commit to the production of an atomic bomb. Less than 2 weeks after Pearl Harbor, a timeline was established that would result in the production of a finished bomb by January 1945. Five promising approaches to bomb production were identified and all were to be explored through the pilot plant stage. The Bureau’s role at this point became “the development of analytical procedures for controlling the purity of critical materials in the reactors and in the bomb.” In this capacity, the Bureau received almost 9,000 material samples on which they performed almost 30,000 analyses.
Work on the bomb progressed through research performed in the military, governmental and educational sectors to the point of the assemblage of a dream team of theoretical and experimental physicists, mathematicians, armament experts, specialists in radium chemistry and in metallurgy, specialists in explosives and in precision measurement at Los Alamos, New Mexico. The Bureau contributed a group from its proximity fuze program and a team dedicated to the purification of U235 scrap so it could be used again. Finally, in July 1945, the bomb was tested successfully. https://www.youtube.com/watch?v=Ru2PWmGIoB8
Though overshadowed by the immensity of the development of the atomic bomb, the WWII era yielded two other amazing advances – namely, the airburst proximity fuze and radar. The airburst proximity fuze allowed for bombs to be detonated in the air prior to impact with the ground which greatly enhanced their destructive power. Using this technology, detonation occurs when radio waves emitted are reflected back to the device with sufficient intensity to indicate close proximity to a large object triggering an electronic switch to initiate the detonation.
The Bureau became involved in work on this type of fuze after the NDRC (National Defense Research Committee) assigned the research to the Department of Terrestrial Magnetism at the Carnegie Institution of Washington in 1940. Within the Bureau, the work fell to the team that had previously constructed the radiosonde and radiotelemeter. Within 6 months, they determined that different types of radio would be necessary for rotating projectiles (used by the Navy in antiaircraft guns) and nonrotating (for the Army and Air Force to use with bombs, rockets and mortars). Only the work on the nonrotating element fell to the Bureau, which focused on the potentials of either an acoustic fuze or a photoelectric fuze. After eliminating acoustic and other methods, testing began using the Doppler effect of reflected radio waves. By early 1941 they had achieved proof of concept but it took almost 2 more years to develop to the point of being used by the military in combat operations.
Testing and development continued and the program outgrew its laboratory space at the Bureau in 1942. In December of that year, with requests for additional fuze types and other related projects, the Bureau consolidated the various projects into the ordnance development administration. Since the face of the war was constantly changing, the fuze projects were as well. A project established to meet one threat might have to be retooled as that threat gave way to another. Fuze designs had to be tweaked to accommodate different types of exploding weapons. For example, the differences presented by the dry battery used in the bomb fuze as opposed to the power source for the rocket fuze. The dry battery was far more temperature sensitive and had a very short shelf life. These limitations meant an alternate power source had to be found – ultimately resulting in a small generator being fitted to the spinning vane of the conventional bomb fuse. This solution all but eliminated the problems of shelf life and temperature sensitivity, and also made the bomb safer to handle, since it wouldn’t detonate unless sufficient wind passed the vane (as in a drop) to produce enough power to trip the fuze.
All of the advances in fuze and detonation technologies dramatically increased the destructive power of exploding weapons used by the U.S. during WWII. In fact, the technology was so powerful, that use of the fuzes was forbidden in circumstances where the enemy might be able to recover a fuze for later analysis or identify its nature simply by observation. For example, bombs incorporating the proximity fuze were not used for D-Day for fears that a fuze might be recovered from the beach at Normandy. As the war neared its end, fuze plants were “monopolizing 25 percent of the total facilities of the electronic industry and 75 percent of all molding plastics firms.”
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All information presented here is drawn from “Measures For Progress: A History of The National Bureau of Standards” (Rexmond C. Cochrane).