The Optical Glass Rivalry

World War I greatly affected and touched the lives of nearly everyone in the United States. Goods like tin and gasoline had to be rationed. Thousands of men enlisted in the army, leaving their families without a male head of the household. Women were forced to fill their husbands' shoes, working in the factories or wherever else needed just to earn a dime. Hard times befell America.


The Geophysical Laboratory, too, did its part to aid the war effort, though not in a way that has been popularized by the media or legend. Up until 1914, the United States imported almost all good quality glass, from Germany. With the start of the war, however, all imports immediately ceased. As the war intensified and America increased its involvement, the need for optical glass skyrocketed. Optical glass was necessary for equipment like range-finders, field-glasses, gun-sights, and periscopes. Soldiers were placed at a higher risk without good quality glass in their instruments.

Workers making glass molds, 1917.



American glass companies did their best to fill Germany’s shoes. Nevertheless, efforts floundered due to the appearance of “lines”, or uneven composition, in the American-made glass. The companies just couldn’t seem to get the glass-making process right.

On March 28, 1917, the Geophysical Laboratory’s director, A. L. Day informed Carnegie Institution of Washington President Woodward that he had several key ideas for how the Laboratory could contribute to the war effort. At the forefront of these ideas was the optical glass problem. Weeks after Day’s proposal, he was approached by George Ellery Hale, a Carnegie astronomer, who was working for the National Research Council. Hale officially petitioned for the Geophysical Laboratory’s help with optical glass, which Day directly accepted.

Workers heating glass in a furnace, 1917.



Geophysical Laboratory scientists immediately set to work. It wasn’t long before they discovered that the primary optical glass manufacturing problem lay not in the glass itself, but on the reaction between the melted glass and the surrounding clay pot. Both materials contained silica, so material from the pot could easily dissolve into the glass mixture. This explained the appearance of “lines.” With the problem pinpointed, the scientists began to analyze American clay for a type that was not silica based.


The Geophysical Laboratory was not the only institution concentrating on the optical glass issue. Since 1915, the Bausch and Lomb Optical Company, the biggest manufacturer of American optical glass, and the National Bureau of Standards, a government agency, had been struggling with the very same concerns. Unlike the Geophysical Laboratory, their progress was slow and the results scarcely improved.

In the spring of 1917, the National Research Council devised an ingenious plan to speed up and improve the optical glass making process. The Council recommended that the National Bureau of Standards join with the Pittsburgh Plate Glass Company and the Geophysical Laboratory with Bausch and Lomb to see who could produce the most good quality optical glass in a given period of time. The rivalry provided more than enough incentive for both teams.

Carnegie invested the most research in the basic physical and chemical compositions of silicates. This focus proved strategic as by October of 1917, the winner of the optical glass race was already evident. Bausch and Lomb was regularly producing almost 40,000 pounds of government-accepted glass per month. By eight months, on the other hand, Pittsburgh Plate Glass had produced none. The failure was caused by a lack of cooperation with their partner, the National Bureau of Standards. No improvement was made, and Day was soon asked to take over their operations.


Despite the gigantic success of Carnegie’s optical glass, the process was not without setbacks. The Wartime Car Administration flat out refused to provide freight cars to transport Kentucky clay to Pittsburgh. Instead, clay pots had to be shipped by express to Pennsylvania at a cost of $80 a pot, when pots only cost $20 to make. In addition to shipping troubles, Carnegie had its fair share with quarrying. After discovering the purest sand available for glass-making, the Fuel Administration destroyed practically all quarrying efforts by failing to provide enough coal to keep the plant in operation during the winter. In the end, Carnegie pulled through, but at a cost of over $175,000 to the institution.

Workers wearing filtration masks, 1917.



In 1919, the Washington Evening Star reported that the National Bureau of Standards claimed sole credit for solving the optical glass problem, when the agency had, in fact, thrown in the towel after failing to achieve sufficient results. Furious, President Woodward wrote a letter to the Secretary of Commerce showing that of almost 700,000 pounds of glass made in the United States during the war, less than three percent came from companies other than Bausch and Lomb.

Day and the Geophysical Laboratory were congratulated and honored for their incredible assistance to the United States during World War I. In a speech given by President Woodward in A. L. Day’s honor, the President predicted that “the historian of the Institution will understand more clearly what has been done than our contemporaries do.” The Geophysical Laboratory saved lives by simply improving the quality of war-time optical glass. This fact leaves one to wonder what would have resulted if Day hadn’t stepped in.

  • Wright, Fred. E., War-time development of the optical industry, Journal of the Optical Society of America, 2, 1-7, 1919.
  • Yoder, Hatten S., Jr., Centennial History of the Carnegie Institution of Washington, Volume III, Cambridge University Press, Cambridge, 2004.
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