Horse-drawn machinery such as the McCormick reaper improved harvesting. Inventions such as the cotton gin reduced the cost of processing. During this same period, farmers began to use threshers and tractors that were powered with steam. In 1892, the first gasoline-powered tractor was successfully made. Mechanical harvesters, planters, transplanters, and other equipment were then developed, further improved agriculture. These inventions increased yields and allowed individual farmers to manage larger farms.