Gray's Latest Improved Horse Powers Threshing Machines and Wood Sawing Machines, 1891

As farmers mechanized barn and farmyard work in the nineteenth century, they began to use stationary power sources. These included devices such as treadmills that converted the movement of animals to drive a variety of agricultural machines. Enterprising manufacturers, like Vermont-based A.W. Gray's Sons, specialized in producing and selling these devices and the machines they were designed to power.