of the chassis. The cooling tower for the engine was at the rear, the driver was positioned at the front and the tractor was mounted on a set of Huber steam engine wheels. Production continued with mainly medium-powered tractors using engines supplied by Buda, Stearns and Waukesha. Huber tractors remained popular throughout the 1920s and early 1930s, but production ended during World War II.
The Sterling tractor, which made a brief appearance between 1893 and about 1895, was made in Sterling, Kansas, to the design of a Mr. Hocket. The front view of the Sterling, with its large chimney-type exhaust, looked similar to a steam traction engine, and it has been suggested that this was a deliberate attempt to make it appear more familiar and less frightening to horses passing it on the road. The Sterling specification even included a whistle, useful for signaling to members of a threshing crew.
With the possible exception of the Huber company, tractor production remained a small-scale business until the end of the nineteenth century; however, during the early 1900s, the numbers of tractors built by some of the leading manufacturers grew significantly. One example was the Hart-Parr company, named after its founders, Charles Hart and Charles Parr, who began designing and making engines while both were engineering students at the University of Wisconsin in Madison.
The Hart-Parr Company
Hart & Parr was established in Madison before the two men graduated in 1896; when they left the university, they were ready to start building stationary engines commercially. The company name was changed to Hart-Parr in 1897, and, as the business expanded, it became obvious that it needed more space to increase its production capacity. The company was moved to Charles City, Iowa, where Charles Hart had spent his childhood, and it had built its first tractor by 1902.
For tractor number one, Hart-Parr used one of its own twin-cylinder engines with a 30 HP power rating and the oil cooling system the partners had developed while studying at the university. The oil-cooled engine remained a Hart-Parr specialty until well into the 1920s, and most of the tractors with this feature were equipped with a distinctive rectangular cooling tower at the front of the tractor. Benefits claimed for oil cooling included avoiding the risk of frost damage. The oil also allowed higher operating temperatures, thereby improving the combustion of low-grade fuels such as paraffin or kerosene.
During its first 20 years of tractor production, the Hart-Parr company concentrated on making tractors suitable for big prairie farms in the United States and Canada. While the first production tractors were designed mainly for delivering power through the belt pulley for threshing, improvements to the transmission allowed some models built after about 1904 to be used for heavy-duty haulage work and later for direct plowing.
Hart-Parr became one of the leading companies in the heavy duty end of the tractor market, and its range was topped by the 60-100 model, which weighed 26.5 tonnes (26 tons) and had rated outputs of 100 HP at the flywheel and 60 HP at the drawbar. Lighter tractors were introduced during the 1920s, including Hart-Parr’s smallest model, the lightweight 10-20, introduced in 1921, which was powered by a two-cylinder engine. After three years, the 10-20 was replaced by the 12-24 E, which was in turn replaced, in 1928, by an improved H version of the 12-24.
A move back up the power scale brought the 28-50 model, powered by two of the 12-24 two-cylinder engines placed side-by-side to provide four-cylinder power. In 1929, Hart-Parr became part of the Oliver Farm Equipment Co., and this group was later taken over by the White Motor Co.
One of the companies providing competition for Hart-Parr at the heavyweight end of the market was the Advance-Rumely Thresher Co. of LaPorte, Indiana. It had already established a reputation in the farm equipment market for building steam engines in stationary, portable and traction versions, plus a highly successful range of threshing machines. Its first move into the tractor market came in 1908, when John Secor joined the company and developed the paraffin-burning engine from which the company’s OilPull brand name came. (see “Designed for Performance”).
This was the third tractor built by Charles Hart and Charles Parr. It was tested in 1903 and was given an 18–30 HP rating, with the power delivered from a two-cylinder engine. The tractor, with Hart-Parr’s oil cooling system, is displayed at the Smithsonian Institution, Washington, DC.
Later Hart-Parr tractors acquired a more conventional layout and also some weight compared with the company’s earlier designs. This is the H12-24 model displayed at the Farm Museum at Milton, Ontario. It was powered by a twin-cylinder engine with the horizontal layout favored by John Deere.
Rumely Makes its Mark
Like its Hart-Parr rivals, the new Rumely engines used oil instead of water for cooling, and most of the production tractors carried a distinctive rectangular cooling tower at the front, which did little to improve forward visibility from the tractor seat. Rumely tractors were popular, and one of their biggest successes was the Model E built for about 12 years from 1911 and equipped with a single-speed gearbox. The official power rating was 30-60, or 60 HP on the pulley and 30 HP at the drawbar, but these figures were easily exceeded when the Model E was tested in Nebraska, producing almost 50 HP in the maximum drawbar pull test and just over 75 HP on the belt pulley.
The 30-60 and the GasPull model with a 35-70 power rating were the top models in the Rumely range. The smaller versions included the Model H tractor introduced in 1919 and rated at 16-30 HP. The output was achieved at 530 rpm from a two-cylinder engine with 178 mm (7 in) bore and 216 mm (8.5 in) stroke. The Model H was one of the old-style models that disappeared in 1924 after the launch of a new range of smaller, lighter OilPulls featuring unitary construction for the first time in Rumely tractors.
This front view of the H12-28 shows the steering wheel offset to the driver’s right-hand side. This sales feature was favored by many of the leading US manufacturers, and it was designed to give a better view from the driver’s seat when working with a plow, helping to keep furrows straighter.
Although the new models were given more modern styling, the distinctive rectangular cooling tower was retained—no doubt pleasing the many Rumely fans—but the new version was lower and less obtrusive. The first batch of four new models announced in 1924 started with the Model L, the smallest version, which had a 15-25 power rating. The OilPull Model M had a 20-35 rating, and this was increased to 25-45 for the Model R. Although the last of the four new models, the Model S, was introduced as part of the lightweight range, by most standards it was still a heavyweight. It tipped the scales at almost 8.1 tonnes (8 tons) and had a 30 HP rated output at the drawbar and 60 on the belt pulley. Nebraska test figures for the lightweight models show that Rumely was continuing to quote output figures conservatively; an example of this is the 25-45 Model R, which had maximum outputs of 32.6 HP at the drawbar and more than 50 HP on the pulley.
More new and updated models followed in the late 1920s, including the company’s first and last six-cylinder model, the Rumely 6; however, these failed to halt a decline in sales. By 1931, when Rumely was facing serious financial problems, the company was taken over by Allis-Chalmers.
Deering and McCormick
While most of the emphasis in the earliest days of the American tractor industry was on replacing steam engines for threshing work, there were exceptions. These included Deering and McCormick, the companies that joined forces in 1902 to form the Chicago-based International Harvester Co.
Deering and McCormick both used small gasoline engines to power tractors designed as self-propelled mowing machines, and they were both available in small numbers from about 1897. The Deering mower was powered by a two-cylinder horizontal engine and was equipped with a 1.5 m (5 ft) wide cutterbar. The McCormick version was called the Auto-Mower and used a 6 HP gasoline engine. Both were designed as small, lightweight machines based on a three-wheeled design, with the single wheel at the front. The Auto-Mower was equipped with tiller steering designed for one-handed operation, while the Deering mower used a small-diameter car-type steering