Horse Gin House at Park Farm, Illogan, Cornwall
This horse gin house dates from the late 18th or early 19th century. These buildings were always round in shape and they housed a wheel or 'gin' that was turned by a horse walking round in a circle. A drive shaft leading from the gin would have a belt pulley on the end used to turn any sort of machinery. In this case there is a hole through the back wall to carry the drive shaft to some threshing machinery that was in the attached barn. This is the origin of the term 'horse power'. For a large piece of machinery you would need more than one horse.
