208 
Application of Steam Power 
.•inchored rope, as in working INIr. Fowler's plough. A hori- 
zontal tubular boiler is mounted upon a wrought-iron framing, 
and balanced upon two plummer-blocks, so that it can be 
instantly and easily adjusted to any level by means of a screw 
under the command of the driver, who has a spirit-level to guide 
him. Tlie cylinders are not fixed to the shell of the boiler, but 
are placed within the framing underneath it ; the steam passing 
by a pipe from the top of the high steam-dome and through a 
stufling-box in one of the plummer-block bearings upon which 
the boiler is suspended, while the exhaust steam is conducted to 
the chimney by a short piece of flexible pipe. The water is sup- 
plied to the boiler by the feed-pijie passing througli a stuffing- 
box in the other plummer-block bearing. Tlie hind-wheels (of 
(y feet diameter with 12-inch broad felloes) are about 9 feet from 
the front wheels, which are of 3^ feet diameter ; so that a short 
depression or elevation in the ground makes but a slight altera- 
tion in the position of the boiler, and the balance-motion allows 
it to be adjusted so as to continue horizontal on inclines of 1 in 
10. The propulsion is effected by an endless pitch-chain from 
a pinion on the crank-shaft (under the boiler, and supported 
in bearings on the frame) to a cog-wheel on the hind-wheel 
axle ; each of these main travelling-wlieels being set tight or 
loose on the axle by means of rings or " straps," which clasp 
like a break. 
Another peculiarity is that the whole is supported upon 
strong springs, which, however, are taken out of action by 
a screw when required ; and the weight, about 7 tons with 
water, &c., is so distributed that rather more than half rests upon 
the hind or driving-wheels. There are two cylinders of 8^ inch 
diameter and 10 inch stroke, making 120 strokes per minute ; 
the working pressure generally GO lbs., but the boiler calculated 
to carry 120 lbs. pressure per square inch : thus, while nominally 
of lO-horse power, it works in reality at some 25 to 30-horse 
power. Over very imperfect roads, up gradients of greater 
steepness th;in even 1 in 10, the engine travels, dragging 6 or 
7 tons' weight of ploughing machinery behind it, without having 
recourse to the " endless rails," tliough in some circumstances they 
would be advisable. A horse is used for steering with a pair of 
shafts. Respecting the cost, Mr. Smith writes me as follows: — 
" ^ly price for an 8-liorsc singln-cylindcr engine, constructed in tlio general 
way, with Lowrnoor plates in fire-liox, and copper ])iece to receive the ttibe at 
the fire-box end (a plan not generally used, but which, I feel as.sured, will be 
found a great .ndvantage), i8 215/. An 8-liorse engine with double cylinders, 
235/. Extra for making locomotive by means of Williams's jiitch-chain, 25/. 
V>\xi these engines I could not recommend tor ]iloughing purposes, on account 
of the wheels not being adapted to travel on loose headlands, when cultivating 
land. What I think would be best calculated for that and other general inn- 
