|The principal feature of the Ferguson System was the three-point linkage.
This allowed trailed implements to be supported on a hydraulic system.
Two drag links attached under the rear axle with a single compression
link connected to the upper rear transmission
case automatically regulating the hydraulic suspension's height. This
allowed lighter implement to be used, with no attached wheels or
separate manual controls. By assisting the tractor to maintain traction
from a combined drag and rotary force to the axle, which kept the rear
driving wheels on the ground, the front steering wheels had improved
contact with the ground. Consequently the "rearing and bucking" of
overloaded tractors was reduced, making tractors much safer for the
Read more on Wikipedia.
A random image I took a while ago, and suddenly it appears on Wikipedia as a central image illustrating the three-point linkage of Massey Ferguson.