A four-wheel-drive tractor was offered in 1920 by the
Nelson people. Equipped with a Wisconsin four-cylinder, 4
x 5 engine, the Nelson was capable of 15 drawbar and 24
brake horsepower. Because of the four-wheel-drive design,
the Nelson had exceptional ground clearance as an inherent
feature. The open face drive wheels were intended
to be self-cleaning. The idea sounded fine, but the Creator
endowed almost every farm with a certain amount of
earth that would push itself right into the wheels and stay
there. The coming of pneumatic tires in the early 1930’s
solved this great problem.