Long before the internal combustion engine was perfected or steam power became popular, horses, mules, cattle, dogs, goats and even sheep were pressed into service to supplement human brawn as a power source. So long as the job was to move a load from here to there, all that was needed was a strong draft animal or two and a suitable harness to connect the animal to the load. However, converting an animal’s linear movement into rotary motion wasn’t as easy.
Probably the first machine that needed turning was the gristmill, developed in the Middle East in about 800 B.C. to grind flour. Fortunately, the gristmill was stationary and could be located next to a stream or river that furnished the driving power through a water wheel. Gristmills could also be turned by windmills. The first recorded instance was in Rome before the time of Caesar Augustus. When sawmills became popular, they too were usually located along a stream. Often a single entrepreneur would build a gristmill and a sawmill side by side and folks from the surrounding area would haul their grain and logs to him for processing.
When threshing machines became popular in Great Britain (during the late 1700s) and in America (by the 1820s) they were turned by hand, a tedious job that required much muscle and sweat. In 1826 it was said of Jacob Pope’s Massachusetts-built threshers that it was “harder work to turn the crank than to swing the flail.” Barns were seldom close enough to a stream to allow the use of a water wheel. While the occasional farmer might have a windmill to pump water, it wasn’t powerful or reliable enough to run a thresher.
In 1822, a man named Howe patented a thresher with a vertical cylinder that was driven by a tethered horse walking on a large circular platform. As the platform revolved, a belt around its circumference drove a pulley on the vertical shaft of the threshing cylinder. Supposedly, the endless-track treadmill tread power was invented in England in the 18th century to drive textile mills, reportedly with shackled prisoners providing the power, although most references I’ve found refer to water power. So treadmills weren’t new. Although slaves, prisoners and even children may have been used at times to run them, animals were the more popular source of power.
Most early “groundhog” threshers (early threshing machines consisting of a spiked cylinder and a fixed concave) were powered by a horse or an ox on a tread power but the new, combined thresher-fanning mills being developed by the Pitts brothers and others required more power than the old leather-belt treadmills could provide. The Pitts brothers (John and Hiram) made many improvements to the groundhog threshers of the day, including an improved treadmill patented by Hiram Pitts in 1830 that used iron tracks and rollers to support the wooden lags (or tread blocks).
Tread powers were built in many sizes. Small versions operated by a dog, goat or sheep ran small machines; huge, four-horse models powered large threshing machines or sawmills. All tread powers, regardless of size, consist of an inclined box or pen into which animals are driven and tied. The floor of the pen is made up of an endless chain of cross planks (lags), each of which is supported and connected to each other and to the drive pulley by arrangements of chains and rollers. There is usually some sort of a centrifugal governor inside the pulley to keep the movement of the platform from “running away” with the animal.
As the animals were made to walk upward and forward, their weight forced the sloping “floor” to move to the rear, turning a belt pulley or a tumbling rod, or moving a lever that drives the machine. A gate behind or a tether at the front prevented the animals from stepping off the rear of the platform, while its movement forced them to keep walking forward. The angle of most treadmills can be adjusted. The steeper the angle the more power that can be applied, within the capabilities of the driving animal, of course.
The slanting surface of the wooden lags could become slippery from manure or moisture and the animal’s hooves were prone to slippage. In 1871 David and Josiah Heebner, Norristown, Pa., patented an improvement to tread powers that allowed the top surface of each tread segment to be level, even though the underside was angled upward. This “level tread” feature “afforded a firm and secure foothold for the horse,” helped alleviate the problem of slippage, and was soon adopted by other manufacturers.
The Westinghouse Co., Schenectady, N.Y., built threshing machines, steam engines, sawmills, and both tread and sweep horse powers. In its 1886 catalog are listed one-, two-, three- and four-horse treadmills, which Westinghouse called “Endless Chain Powers.” The catalog claimed the tread powers were: “in every respect a substantial and efficient power, and adapted to all the uses farmers require power for; such as threshing, feed cutting, wood sawing, etc.”
An 1882 testimonial from John A. Swart, Mt. Idaho, Idaho Territory, reads in part: “As to the three-horse tread power, will say I think it is the power for all frontier farmers, being adapted for threshing, chop mill, wood saw, or for small sawmills for making fencing; it being very economical, requiring no driver, the governor regulating the motion. (The power) is durable, being well made and of good material; is not liable to get out of order; have worked several horses and mules and find no trouble in breaking them in, using no harness.”
Tread powers were limited to, at most, four-horse units and not many of these larger versions were practical. As threshing machines became larger, with feed and straw conveyors, as well as the new “vibrators” (or straw walkers), more power was required and sweep horse powers were the answer, for a while anyway – until the “iron horse” came puffing and smoking upon the scene. FC
For more on tread powers and how they are used today, read Horse Treadmill Powered Freezer from the April 2011 issue of Farm Collector.
Sam Moore grew up on a farm in western Pennsylvania. He now lives in Salem, Ohio, and collects antique tractors, implements and related items. Contact Sam by e-mail at firstname.lastname@example.org.