The optical-glass industry had never been developed in America, our field glasses being supplied with lenses of European glass, and principally German glass. In 1914 the imports of optical glass were $641,000 in value. The following year they were almost nothing. The advance of the German army toward Paris encompassed the glass plants of Belgium and many of those of France. England needed the entire output of her own glass factories.
In the autumn of 1914 the American optical-instrument makers began to develop an optical-glass industry, largely stimulated by the possibility of obtaining heavy orders at high prices from the British, French, and Russian governments. The most important work was done by the Bausch & Lomb Optical Co., of Rochester, N. Y.; the Spencer Lens Co., of Buffalo, and the Pittsburgh Plate Glass Co., of Pittsburgh. They were aided by the United States Bureau of Standards and by the geophysical laboratory of the Carnegie Institution. The Bureau of Standards established a laboratory at Pittsburgh where experiments were conducted with 30-pound pots of glass.
Optical glass differs greatly from ordinary glass. It must be clear, without striae, and there must be no strains in it, resulting from the final stirring and cooling. It must give a high transmission of light.
About the time of America's declaration of war the American experiments had produced glass suitable for optical instruments. This glass, however, was being turned out in quantities quite insufficient to meet the demand during the first few months.
In addition to the difficulties surrounding the glass supply, there was only a limited number of establishments capable of manufacturing field glasses after the glass was procured. These concerns were located principally in Rochester, N. Y., where they had been manufacturing a wide variety of optical instruments, including opera glasses, camera lenses, scientific and educational apparatus, battery commanders' telescopes, marine glasses, microscopes, and gun sights. In order to meet the war requirements of America for field glasses, these factories had to install large quantities of new equipment and to run day and night. The equipment consisted of lens-grinding apparatus, lathes, dies, and automatic screw machinery.
In addition to the Rochester factories there was a concern in Denver, Colo., the Weiss Electrical Instruments Co., which in a smaller way had been manufacturing surveyors' levels and other engineering apparatus. The Talbot Reel & Manufacturing Co., of Kansas City, had been making fishing reels in a small plant about 30 feet square. This factory was purchased in 1917 by Mr. L. Harris, who, after finishing a contract for gun sights for the Ordnance Department, built a factory especially for the production of Army field glasses and reached the quantity manufacture of these instruments before the armistice came. The chief center of supply, however, continued to be Rochester, where the plants of Bausch & Lomb, the Gundlach-Manhattan Optical Co., and the Crown Optical Co. are located. These factories expanded many times, and the output of field glasses went beyond what the executives at the outset of the enterprise imagined could be possible.
The Bausch & Lomb Co. was started in Rochester about 50 years ago by J. J. Bausch, who was born in Germany. The plant developed gradually, making a full line of spectacle lenses and optical instruments. The Carl Zeiss Works, of Jena, Germany, had a financial interest in the plant, and Bausch & Lomb had a financial interest in the Zeiss plant. This connection, however, was dissolved in 1915, when Bausch & Lomb took on contracts for the manufacture of field glasses for the British, French, and Russian governments.
Before 1914 this concern had never manufactured more than 1,800 pairs of field glasses in a year. The output was speeded up until in November, 1918, a total of 3,500 pairs was being produced each week, while the development was aiming toward an output of 5,500 pairs of glasses per week beginning in January, 1919. At the date of the armistice the Bausch & Lomb factory had a floor space of 32 acres and employed 6,000 men and women.
The Gundlach-Manhattan Co., which had made camera lenses chiefly, was eventually able to produce 600 pairs of field glasses a week. The Crown Optical Co. was not so rapid in its expansion; and in late 1917 the Navy Department commandeered it and thereafter operated it in charge of Lieut. Commander L. C. Scheibla. Under naval management the output of this factory increased so that the Signal Corps was able to obtain from it about 1,200 pairs of high quality field glasses each week, the plant continuing also to supply the needs of the Navy.