Though McCormick offered reapers for sale in 1834, he seems to have sold none in that year, nor any for six years afterwards. He sold two in 1840, seven in 1842, fifty in 1844. The machine was not really adapted to the hills of the Valley of Virginia, and farmers hesitated to buy a contrivance which needed the attention of a skilled mechanic. McCormick made a trip through the Middle West. In the rolling prairies, mile after mile of rich soil without a tree or a stone, he saw his future dominion. Hussey had moved East. McCormick did the opposite; he moved West, to Chicago, in 1847. Chicago was then a town of hardly ten thousand, but McCormick foresaw its future, built a factory there, and manufactured five hundred machines for the harvest of 1848. From this time he went on from triumph to triumph. He formulated an elaborate business system. His machines were to be sold at a fixed price, payable in installments if desired, with a guarantee of satisfaction. He set up a system of agencies to give instruction or to supply spare parts. Advertising, chiefly by exhibitions and contests at fairs and other public gatherings, was another item of his programme. All would have failed, of course, if he had not built good machines, but he did build good machines, and was not daunted by the Government's refusal in 1848 to renew his original patent. He decided to make profits as a manufacturer rather than accept royalties as an inventor. McCormick had many competitors, and some of them were in the field with improved devices ahead of him, but he always held his own, either by buying up the patent for a real improvement, or else by requiring his staff to invent something to do the same work. Numerous new devices to improve the harvester were patented, but the most important was an automatic attachment to bind the sheaves with wire. This was patented in 1872, and McCormick soon made it his own. The harvester seemed complete. One man drove the team, and the machine cut the grain, bound it in sheaves, and deposited them upon the ground. Presently, however, complaints were heard of the wire tie. When the wheat was threshed, bits of wire got into the straw, and were swallowed by the cattle; or else the bits of metal got among the wheat itself and gave out sparks in grinding, setting some mills on fire. Two inventors, almost simultaneously, produced the remedy. Marquis L. Gorham, working for McCormick, and John F. Appleby, whose invention was purchased by William Deering, one of McCormick's chief competitors, invented binders which used twine. By 1880 the self-binding harvester was complete. No distinctive improvement has been made since, except to add strength and simplification. The machine now needed the services of only two men, one to drive and the other to shock the bundles, and could reap twenty acres or more a day, tie the grain into bundles of uniform size, and dump them in piles of five ready to be shocked.