Soon after the Franco-Prussian War, an agent of the company visited Prussia and found the royal and private gun factories equipped with old and inferior machinery and the armories bare. Mr. Pratt was sent for, and returned to Hartford with orders from the German Government for $350,000 worth of gun machinery. During the next few years Mr. Pratt made no less than ten trips to Europe, taking orders aggregating over $2,000,000 worth of machinery. When the panic of 1873 prostrated the industries of the United States, Pratt & Whitney had orders, mostly foreign, which kept them busy until 1875. Their equipment of the three royal armories of Spandau, Erfurt and Danzig resulted in an improvement in quality of output and a saving of 50 per cent in wages. Pratt & Whitney’s production of gun-making machinery alone has run into many millions of dollars, and there are few governments which have not at one time or another purchased from them. Pratt & Whitney from the start were leaders in establishing standards, particularly in screw threads. Their gauges for pipe threads have for years been the standard for the country. The troubles which arose from the lack of agreement of standard gauges and the growing demand for interchangeable bolts and nuts led to a demand on the company for a set of gauges upon which all could agree. In undertaking this work Pratt & Whitney examined their own standards of length with reference to government and other standards in this country and abroad. The results were conflicting and very unsatisfactory. By different measurements the same bar would be reported as above and as below the standard length, and the investigation produced no results which could be used for a working basis. At length Prof. William A. Rogers of Harvard University, and George M. Bond, backed by the Pratt & Whitney Company, developed the Rogers-Bond comparator with which they determined the length of the standard foot. When they began, the length of the yard and its subdivisions varied with the number of yardsticks. Professor Rogers’ work was based on line measurement rather than the end measurement which had held sway from the time of Whitworth and which is now generally recognized to be inferior for final reference work. Professor Rogers went back of all the secondary standards to the Imperial Yard in London and the standard meter in the Archives at Paris. He obtained reliable transfers of these, and with the coöperation of the United States Coast Survey, the most delicate and exhaustive comparisons were made of the standard bars prepared by him for the use of the company with the government standard yard designated “Bronze No. 11.” Many thousands of dollars and three years of time went into this work. The methods used and the results obtained were examined and reported upon by a committee of the American Society of Mechanical Engineers, and the conclusion given in their report is as follows: