178 
Application of Steam Poiocr 
ward, just as a paddle moves a steam-boat. As the wheel-work 
actuated the tiller from the axis of the carriage-wheels or broad- 
roller supporting the framework of the machine, the motion 
of the tiller was derived from the traction of the machine, just as 
that of a drill cup-barrel is ; but the patentees contemplated the 
use of " any other suitable motive agent " as well as horse-power, 
and a steam-engine mounted upon the platform of the machine, 
and driving the travelling-wheels, would liave embodied the prin- 
ciples of action followed in subsequent inventions. 
In July, 1847, Mr. Paul patented a revolving drain-cutter and 
a revolving subsoiler— the latter consisting of a horizontal axle, 
supported by a frame for raising or lowering it, and having several 
naves or bosses, with curved tines or teeth affixed to them, and 
midway upon the axle was a wheel driven by an endless chain 
from a horse-power windlass, which slowly advanced, dragging 
the subsoiler behind it. The teeth, when in the ground, travelled 
in the same direction as the machine, making tlieir cut upwards, 
and so bringing up the sub-soil in front of the axle ; whereas in 
the former machine the cut was downwards, moving the soil 
backward. This action of course opposed the onward progres- 
sion. In October of the same year. Sir John Scott Lillie 
patented a tillage apparatus, — including an axle extended horizon- 
tally across a carriage, and driven by toothed gearing from one of 
the travelling-wheels, or more directly from a steam-engine 
placed upon the machine, the carriage itself being propelled by 
the engine winding along a fixed rope. Radial or curved pins, 
tines, hoes, or suitably-shaped points, for breaking up the land, 
were fixed on this axle, and, rotating rather rapidly in a direction 
opposed to the machine's advance, broke up and comminuted 
the ground. 
In July, 1849, Mr. James Usher, brewer, of Edinburgh, 
patented a more successful cultivator, to which I must devote 
a little space. A portable steam-engine is mounted upon a 
framework mainly supported by a pair of broad-fellocd wheels 
or a wide roller, and also by a front pair of wheels turning in a 
transom for steerage. A lever-frame at the bac k of the carriage 
supports a horizontal transverse shaft, which may thus be raised 
or lowered at pleasure, and both this shaft and the main bearing- 
wheels are driven by toothed gearing from the engine crank- 
shaft, the wheels rotating so as to give a slow progressive motion 
to the machine, and the sliaft revolving at greater, though mode- 
rate, sjjeed. On this sliaft are fixed four or more discs or plates, 
each carrying three ploughs of a curved form, so arranged that 
no two shares strike the ground at the same instant. These 
ploughs (or teeth, tines, or other instruments) penetrate the 
earth in the opposite direction to that in which the machine is 
