to the Cultivation of tite Land. 
Ill 
for accomplishing, at one operation, either the turning-up of 
rough spits or the pulverising of fine mould, and this at depths 
hitherto unheard of, excepting in spade-husbandry. 
But now let us look at the difficulties to be overcome, and the 
measure of success already attained by various inventors. Break- 
ing away from traction implements altogether, even from the 
idea of rolling-forkers, you have to devise cutting shares, or 
blades, or picks adapted to rotary motion ; and, an infinite 
diversity of form being open to us, only experiment can deter- 
mine what peculiar cutter is best suited to certain ends. Then, 
in applying the power: if the digger be attached to a locomotive 
engine, power is required for propelling a ponderous machine at 
a slow pace over the ground, and on lands where the inclines 
are steeper than say one in eight or ten, this swallows up all the 
mechanical advantage otherwise gained. A portable steam- 
engine alone is a very heavy weight on moist arable land ; and 
when a massive framework and machinery are added, the travel- 
ling-wheels are liable to sink into the soil, not only rendering a 
great expenditure of force necessary for propulsion, but injuring 
the ground by undue consolidation. It is difficult, also, to avoid 
fine and complicated mechanism, very costly in the first outlay, 
and too expensive and troublesome for the farmer to keep in 
order in regular field-work. And, indeed, there may be wheels, 
and pitch-chains, and connecting-rods enough to absorb all the 
promised economy of power, and cause your cultivator to 
compare discreditably Avith the rope-traction system. On steep 
hill-sides, of course, a locomotive cannot travel ; and wire-rope 
haulage, with its own especial implements, must be resorted to, 
unless rotary delving be found so effective a process as to be 
Avorth accomplishment by the method of transmitting power 
from a stationary engine with a rapidly-flying endless hemp rope. 
Now, the idea of attaching radial cutters about a shaft or 
drum having a rotary motion not derived from its oion rolling is 
very old, although newer than that of rolling cultivators. In 
July of the year 1846, Messrs. Bonser and Pettitt patented a 
tiller, formed of a cylindrical shaft or drum, having a number 
of radial cutters, prongs, or tines, either straight or curved, 
attached to it at right angles and arranged round it spiralwise, 
so as to present the appearance of a screw. This tiller was 
placed across the back of the machine, with its axis at right angles 
to the direction in which the machine travelled, and it was caused 
to revolve by toothed gearing with considerablv greater velocity 
than if it had simply rolled, the direction of rotation being the 
same as that of the carriage- wheels of the machine ; so that the 
cutters entered the soil downwards, tossing the crumbled earth 
backward, and their action tended to propel the machine for- 
VOL. XX. N 
