Peter Shirk didn't have sufficient capital or a large enough shop to expand production to meet the increasing demand for his tractors. He apparently sold the manufacturing rights for the tractor to the Otto Gas Engine Works in the fall of 1911. A brochure on the 'Otto Gasoline Tractor,' published before the end of 1911, included a photograph of a tractor with Peter Z. Martin, Peter Shirk's son-in-law, at the wheel. This photograph, used earlier in a flyer put out by the Blue Ball Machine Works, was of a Shirk tractor. Such use of the photograph would seem to indicate that Otto took up production of the tractor without finding it necessary to alter Shirk's design.
Specifications of the Otto gasoline tractor, designed by Peter Shirk, show the type of vehicle which Shirk had been building for almost two years prior to selling out to the Otto Company. The frame was made of steel channels and the axles were cold-rolled steel shafting. Drive fromthe Otto engine to the transmission was by a shaft with bevel gears. The transmission, which was in constant motion, provided forward speeds of 2? and 5 miles an hour as well as reverse. The constant mesh transmission required only the clutch shaft, the master wheels, and the axles and tractor wheels to be stopped and started when the vehicle was reversed. The gear change from high to low gear was simple and straight-forward: the driver had merely to shift from high gear to neutral and then press the 'palm trip' on the shift lever to engage low gear.
Otto guaranteed their tractors to deliver fifty per cent of the engine's brake horsepower to the draw bar. The tractor bulletin stated: 'An attachment can be furnished for mowing.' No doubt the mowing bar attachment for the Otto tractor was supplied by Shirk, who had been manufacturing it since mid 1910 asan optional extra for his own line of tractors.
The Otto could be converted for any kind of farm work by merely loosening a set-screw and putting the gears out of mesh. A friction clutch could then be used to power a thresher, sheller, shredder, buzz saw, or other equipment.
The Otto line, to which was added just one model not previously offered by Shirk, is shown in the table on the following page.
After discontinuing the manufacture of tractors, Peter Shirk concentrated on his other inventions, manufacturing a tobacco cutter called 'The Handy Tobacco Shear,' which permitted anyone to cut tobacco without stooping over. It was basically a long-handled shear with one-wheel support and could be pushed down a row of tobacco. One specialty of the Blue Ball Machine Works after 1911 was the installation of electric light plants in homes andbusinesses throughout eastern Lancaster County. Peter Shirk kept two Shirk tractors for use around the machine works. The tractors wereused in 1914 to drag a large boiler weighing several tons to the shop for repairs. No Shirk tractors are known to have survived to the present day.The Blue Ball Machine Works is still in business at the present time, now operated by Peter Shirk's grandson, George P. Newswanger.
I would like to thank Mrs. Esther Newswanger, Peter Shirk's daughter, who provided brochures on the Shirk and Otto tractors and all of the photographs used to illustrate this article. The other major source of information was the back file of the New Holland Clarion available for research at the Lancaster County Historical Society, Lancaster, Pennsylvania.