<P> Hillside leveling has several advantages . Primary among them is an increased threshing efficiency on hillsides . Without leveling, grain and chaff slide to one side of separator and come through the machine in a large ball rather than being separated, dumping large amounts of grain on the ground . By keeping the machinery level, the straw - walker is able to operate more efficiently, making for more efficient threshing . IH produced the 453 combine which leveled both side - to - side and front - to - back, enabling efficient threshing whether on a hillside or climbing a hill head on . </P> <P> Secondarily, leveling changes a combine's center of gravity relative to the hill and allows the combine to harvest along the contour of a hill without tipping, a danger on the steeper slopes of the region; it is not uncommon for combines to roll over on extremely steep hills . </P> <P> Newer leveling systems do not have as much tilt as the older ones . A John Deere 9600 combine equipped with a Rahco hillside conversion kit will level to 44%, while the newer STS combines will only go to 35% . These modern combines use the rotary grain separator which makes leveling less critical . Most combines on the Palouse have dual drive wheels on each side to stabilize them . </P> <P> A leveling system was developed in Europe by the Italian combine manufacturer Laverda which still produces it today . </P>

Who invented a machine for harvesting grain that allowed farmers to plant much larger crops