Wisco)sini State Drainage Association



perhaps, give him a few more square inches of bearing surface.
Even with this additional foot area the horse is at a decided dis-
advantage. It is true the horse may become partially accus-
tomed to using marsh shoes and when there is danger of miring
he will not become excited and struggle to free himself. How-
ever, it is dangerous at best to attempt to accustom a horse to
work where there is danger of miring down. The struggle and
strain that a horse is likely to make may result in his serious
injury. Most anyone would welcome a mechanical power that
will save horses from this danger.
  Tile ditching is the feasible method of removing the under-
ground water. The disinclination - of good labor to diteh on
marsh lands or in fact to do ditching of any kind, makes it nec-
essary to adapt mechanical power in ditching. A tractor is
specially adapted to furnishing the power for pulling most any
type of ditching machine. The horse ditching machines require
from six to eight horses. A tractor will furnish this amount
of power easily. It can be kept going throughout the working
day. It will require less man power to operate the entire outfit
and it ought to go on the soil where horses would be impracti-
cal.
  A tractor can travel on land when it is impossible to get on
it with horses and at times even with men. A tractor weighs
all the way from 3,000 to 30,000 lbs; the average weight of a
draft horse is about 1600 lbs.; and the average weight of a man
is 180 lbs. A 60 H. P. tractor weighing 24,000 lbs. and
equipped with what is known as a Caterpiller or flat wheel
6'-4" long and 24" wide, has a pressure of about 5 to 6.4 lbs.
to the square inch. The same machine equipped with a 30-inch
track would have a pressure of 4.4 pounds per square inch. A
wheel machine of about the same horse power with a 69" wheel
has a pressure of about seven lbs. A Caterpillar machine
weighing 6,000 lbs. has 1,152 sq. in. of traction surface This
weight machine has a pressure on the ground of 4.3 lb. to the
sq. in. The same machine can be equipped with a special track
which reduces the pressure to about 21/2 lbs. The horse has a
pressure of about 10 to 12 lbs. and a man has a pressure of
about six pounds. The wheel tractor of about 25 B. H. P.,
weighing about 7500 lbs. and having a weight of 5600 lbs. op



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