Hay is grass that has been cut and dried for use as fodder for farm animals. Numerous tools and machines have been designed over the years to process it. The earliest haying tools were homemade for manual field work. Scythes were used to cut the grass, rakes to pile it into windrows, and pitchforks to fluff the hay and toss it into stacks or onto wagons.

Efforts to mechanize haying operations began in the early 1800s with the invention of haying machines, or tedders. Their development coincided with that of mowing machines. About 1820, Englishman Robert Salmon developed a haying machine which mechanically turned the cut grass for drying. His device consisted of curved iron teeth projecting from a horizontal cylinder that turned as the machine was drawn forward. Another Englishman, Thomas Wedlake, produced an improved version of Salmon's tedder in 1843, featuring a...