Shades of Green

The Hart-Parr Co. used a unique, but spectacular demonstration where a small tractor such as the Model 12-24, with a trained operator, would seem to lift itself off the ground, stop and reverse back to earth smoothly, using heavy leather straps attached to the front axle and rear wheels through overhead pulleys. The demonstration was called the 'Bootstraps Test' and was carried out on farms, dealer lots and at fairs around the country. Marketing materials associated with the Bootstraps Test called particular attention to the fact that the tractor was light enough to lift its own weight, that it could do so with no throttling - proving that the governor was smooth and automatic, and the tractor remained fairly even -proof of the effectiveness of the differential drive system.

Gerold Mettler, owner of Mettler Implement in Menno, S.D., re-creates the 'Bootstraps Test' with his 1928 Hart-Parr 12-24 tractor and lift frame he constructed of wood, just as the originals were. Gerold employs steel cable rather than leather straps because it is safer and easier to find. Gerald's demonstrations were a big hit at the 14th Annual HPOCA National Summer Show, where under his steady hand, the tractor pulled itself up, held, and lowered itself back down with smooth and controlled power. Gerold says the test requires some careful practice and attention to clutching and braking, but it isn't really dangerous.