Farmers for thousands of years harvested grain crops by hand. They could cut the stalks, stack them in large piles, then store them in a silo. It took many people to do these tasks, until in 1831 Cyrus McCormick (and later others) developed the reaper, a machine that cuts the stalks with reciprocating knifes after a reel leans the standing grain towards the rack, platform or endless canvas. McCormick's reaper required two people, one to ride and guide the horse pulling it, and the other to rake cut grain off the platform into a windrow on the ground.
McCormick said his reaper cut as much grain in one day as four or five men with cradles or 12 to 16 using hand sickles.The manual raked reaper developed into a self raking and later self binding reaper. The platform canvas conveys the grain to two vertical canvases parallel to one another and moving in different directions. By these the grain is elevated and conveyed to the sheaving platform. The mechanism on the sheafing platform collects the grain as it is being constantly poured upon it and separates it into sheaves; next a binder attachment binds the sheaves and releases them, allowing them to fall straight to the ground.
These machines were pulled by horses and the moving parts were powered by a large wheel that rotated when the machine was pulled forward. Many names for this wheel including traveling wheel, traction wheel, drive wheel, harvester wheel and later, bull wheel. This wheel and the whole machine depended on the friction or traction between its outer diameter and the ground. When the ground was wet or muddy, problems occurred. The more the machine did, the more energy and so traction was required. The first problem, when the bull wheel skid, was the reciprocating blade of the cutter bar would stop reciprocating and the grain would wad up on the fingers ripping up by the roots and necessitate manual clearing.
From the 1830's to the 1940's when farm implements were powered by the bull wheel, many improvements and attachments were adding to solve the slipping bullwheel. This was mostly done by individual ingenious farmers.
1. Bigger Spikes or lugs on the bull wheel
[[http://books.google.com/books?id=OTLo5F0SQ28C&pg=PA220&lpg=PA220&dq=%22bull+wheel%22+cleats+binder&source=bl&ots=JksYMZ1pUs&sig=PmDEqw6gjrVp-nAAt9fL0UOf5Q4&hl=en&ei=IvYcTLeoF8X_lgfB65zyDQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBUQ6AEwAA#v=onepage&q=%22bull%20wheel%22%20cleats%20binder&f=false| "In marshy riceland the bull wheel had to be fitted with large"lugs" instead of with the cleats used in wheat fields."]]
2. Wider wheel
3. Double or 2 bull wheels
4. [[http://www.machine-history.com/McDaniel%20Bull%20Wheel|Extra smaller diameter bull wheel]] that only touched the ground when the primary bull wheel sank or slipped in the wet ground. "|The invention primarily consists in mounting a broad tread roller adjacent to the bull wheel of a binder or harvester and in having said roller normally elevated above the ground surface on which the bull wheel rests and has movement, the roller attachment and the bull wheel having such relative dimensions that when the bull wheel sinks a short distance into soft ground or mud the roller will come in contact with the surface of the ground and, having a broad tread, will prevent sinking of the ground wheel a greater distance into the ground and thus hold the machine up so that the mechanism of the binder or harvester may effectively perform the functions for which it has been devised."
5. [[http://www.machine-history.com/1915%20Harvester%20High%20Wheel%20Attachment|Giant 8 foot attached bull wheel]] that the original bull wheel road inside of and the giant wheel surrounded complete sheafing platform and binder. This attachment was a [[http://www.machine-history.com/Revolving%20Track%20Wheel%20for%20Binder%20Bull%20Wheel|huge wooden wheel without spokes]] and wide enough for the bull wheel to travel in smoothly. There is a rim 2 or 3 inches high to keep the bull wheel from slipping out. In use, the bull wheel is jacked up high enough to slip the track under it, and the machine is them ready to travel.
6. Keg Float
[[http://books.google.com/books?id=njBLAAAAMAAJ&pg=PA290&lpg=PA290&dq=%22+bull+wheel%22+%22keg+float%22&source=bl&ots=EvdFASb6Dq&sig=idEE0EfPVw0qiIhhEQ8pV73SXYo&hl=en&ei=2gUdTO_gA4L6lwfU0Z2nDg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBUQ6AEwAA#v=onepage&q=%22%20bull%20wheel%22%20%22keg%20float%22&f=false|The roller, or keg float,]] is made by passing a piece of 1/2 in. pipe, about 3 ft. long, through holes bored in the center of the heads; this axle is then attached to the binder frame with iron brackets, so as to be carried behind the bull wheel, and about 3 in. above the surface, when the binder is set. By using the tilting lever, a part of the machine's weight may be thrown on the keg at any time.
7. A ICE engine mounted to drive all the machinery.
In applying a gas engine as a power drive on the harvester, the bull chain is first taken off entirely, then the engine power is applied to the main sprocket drive of the harvester so that the engine operates the entire mechanism of the machine and the horses have only to pull and guide the binder. The bull wheel having no power to deliver, merely carries the binder and keeps up on the ground even in wet seasons. Disadvantages of the small engine was cost and the added 150 to 200 pounds of weight.
8.[[http://en.wikipedia.org/wiki/Power_take-off| PTO]] In the early 1920s International Harvester tractors offered a improvement on the bull wheel, the power takeoff.