At the present time American manufacturers are in a position to make instruments of precision equal to the best European product, and the industry will continue, provided there is an adequate market for its product. Such a market will exist if the universities and commercial laboratories of the country will obtain scientific apparatus from American manufacturers rather than import it from abroad as has heretofore been the custom.

In April, 1917, the most serious problem in the situation was the manufacture of optical glass. Prior to 1914 practically all of the optical glass used in the United States had been imported from abroad; manufacturers followed the line of least resistance and preferred to procure certain commodities, such as optical glass, chemical dyes, and other materials difficult to produce, direct from Europe rather than to undertake their manufacture here. The war stopped this source of supply abruptly, and in 1915 experiments on the making of optical glass were under way at five different plants—the Bausch & Lomb Optical Co. at Rochester N. Y.; the Bureau of Standards at Pittsburgh, Pa.; the Keuffel & Esser Co. at Hoboken, N. J.; the Pittsburgh Plate Glass Co. at Charleroi, Pa.; the Spencer Lens Co. at Hamburg, Buffalo, N. Y.

By April, 1917, the situation had become acute; some optical glass of fair quality had been produced, but nowhere had its manufacture been placed on an assured basis. The glass-making processes were not adequately known. Without optical glass fire-control instruments could not be produced; optical glass is a thing of high precision and in its manufacture accurate control is required throughout the factory processes. In this emergency the Government appealed to the Geophysical Laboratory of the Carnegie Institution of Washington for assistance.

This laboratory had been engaged for many years in the study of solutions, such as that of optical glass, at high temperatures and had a corps of scientists trained along the lines essential to the successful production of optical glass. It was the only organization in the country with a personnel adequate and competent to undertake a manufacturing problem of this character and magnitude. Accordingly, in April, 1917, a group of its scientists was placed at the Bausch & Lomb Optical Co. and given virtual charge of the plant; its men were assigned to the different factory operations and made responsible for them. By November, 1917, the manufacturing processes at this plant had been mastered and large quantities of optical glass of good quality were being produced. In December, 1917, the work was extended, men from the Geophysical Laboratory taking practical charge of the plants of the Spencer Lens Co. and of the Pittsburgh Plate Glass Co.

The cost to the Geophysical Laboratory of contributing to the Government the solution of the optical glass problem amounted to about $200,000, but the results attained surely more than justified these expenditures. These results could not have been attained, however, without the hearty cooperation of the manufacturers and of the Army and Navy, which assisted in the procurement and transportation of the raw materials. An ordnance officer was in charge of the Rochester party from the Geophysical Laboratory and was responsible for much of the pioneer development work accomplished there. It was at this plant, that of the Bausch & Lomb Optical Co. at Rochester, that the methods of manufacture were first developed and placed on a production basis. The Bureau of Standards aided in the development of a chemically and thermally resistant crucible in which to melt optical glass; also in the testing of optical glass, and especially in the testing of optical instruments. The Geological Survey aided in locating sources of raw materials, such as sand of adequate chemical purity.

By February, 1918, the supply of optical glass was assured; but the manufacture of optical instruments was so seriously behind schedule that a military optical glass and instrument section was formed in the War Industries Board and took charge of the entire optical instrument industry of the country. Through the efforts of its chief, Mr. George E. Chatillon, of New York, the entire industry was coordinated. By September, 1918, the production of fire-control instruments in sufficient quantities to meet the requirements of both the Army and Navy during 1919 was believed to be assured.

To the accomplishment of this result the Ordnance Department contributed most effectively. The information and long experience of Frankford Arsenal in instrument manufacture and in the work of precision optics were placed at the service of contractors; trained officers of the Ordnance Department were stationed at the different factories; in many factories these officers rendered valuable aid in devising and developing proper and adequate factory operations, in establishing production on a satisfactory basis, in securing the proper inflow of raw materials, in devising testing fixtures, in establishing proper manufacturing tolerances, and in testing the performance of the assembled instruments. Schools for operatives in precision optics were established at Frankford Arsenal, Philadelphia, Pa., at Rochester, N. Y., and at Mount Wilson Observatory, Pasadena, Cal. To many contractors financial aid had to be extended. The fire-control program required, in short, all the available talent and resources of the country to carry it to a successful finish.

The general procedure adopted by the Ordnance Department was to assign the more difficult instruments to manufacturers who had had experience along similar lines. To others, who had produced articles allied only in a distant way to fire-control instruments, less intricate types of instruments were awarded. In certain instances the optical elements were produced by one firm, the mechanical parts by another, the final assembly of the instrument being then accomplished by the latter.

Because our Army had adopted a number of French guns for reproduction here, it became necessary to build sights for these weapons according to the French designs. This gave us much trouble, not only because of the delay in securing samples and drawings from France, but because of the difficulties in producing articles from these French drawings by American methods and with American workmen.