In the design which we have laid down, the cylinder, for instance, can be used to make four, six, eight, and twelve cylinder motors. As this is the most intricate part to make, immense facilities could be provided to produce them in large quantities for the use of many concerns who could manufacture the balance of the motor. Nearly all small parts and numerous large and important ones would also be interchangeable. This would not only speed up production but would be of the utmost importance in connection with repairs and replacements. A full line of motors made according to this plan would line up about as follows: Rated Maximum Weight per Type Horse-power Horse-power Weight Horse-power 4 110 135 375 2.7 6 165 205 490 2.3 8 225 275 535 1.9 12 335 410 710 1.7 Respectfully submitted, (_Signed_) J. G. VINCENT. (_Signed_) E. J. HALL. On June 4 Hall and Vincent finished a layout of an 8-cylinder engine, and presented the drawings and received an order to build ten sample engines, and on June 8 the Packard Company arranged for pattern-making, production work, etc. This motor after intensive work on detail drawings was put into preliminary production. The first one was delivered to Washington, July 3, 1917. In the making of the sample engine Mr. Vincent’s company placed its factory organization at the disposal of the government, and through Mr. Vincent’s untiring efforts and enthusiasm the first motor was completed within the sixty days. The other companies which aided in the work of building this motor were: The General Aluminum and Brass Manufacturing Company of Detroit made bronze-backed, babbitt-lined bearings and aluminum castings. The Cadillac Motor Car Company of Detroit made the connecting-rods, connecting upper-end bushings, connecting-rod bolts, and rocker-arm assemblies. The Cadillac Company had perfected the design of connecting-rods of the forked or straddle type, and had been using them for several years in their 8-cylinder engines. The Parke Drop Forge Company of Cleveland made the crank-shaft forgings. These forgings completely heat-treated were produced in three days, simply because Mr. Hall gave them permission to dig out the Hall-Scott dies which were used in making the first Liberty crank-shaft forgings. Hall-Scott Motor Car Company of San Francisco supplied all the bevel-gears out of its stock for the standardized line of Hall-Scott 4, 6, 8, and 12 cylinder aeroplane engines. The L. O. Gordon Company of Muskegon made the cam-shafts. The Hess-Bright Manufacturing Company of Philadelphia made the ball-bearings.