496 Report on the Trials of Implements at Wolverhampton. 
wheels are imdcrncath the water-tank and foot-plate, the engine travels fire- 
box end foremost. This arrangement is necessary in order to obtain direct 
driving of the road or traction gear (which consists of simple spm-wheels on 
one bide of the boiler comnmnicating motion from the crank-shaft to the main 
travelling-wheels, whose axle lies immediately under the crank-shaft), and 
also to make room for the two horizontal rope-drums of large diameter, one 
imderneath the boiler between the main-wheel axle and the firebox,' the 
other behind that axle and luiderneath the smoke-box. Two upright shafts- 
on the opposite side of the boiler to the road gear, connected together by 
small spur-wheels and driven by a pair of bevel-wheels from the crank-shaft, 
communicate motion to the two drams by spur-pinions engaging with the 
cog-teeth upon their upper flanges. Each rope-drum, with its guide-ndlers 
and automatic coiling motion, is centred, as u.sual, upon a stud ; and by 
Tuiscrewing four nuts from bolts which attach the stud of one drum to a plate 
riveted to the shell of the boiler, and similarly unscrewing four nuts which 
attach the other drum-stud to a curved ])late projecting in the rear of the- 
smoke-box, both drums, with their self-contained gear, may be removed. 
The engine then becomes a simple self-propelling engine, adapted for general 
farm or other purposes; and when again required for cultivation the drums- 
can be readily replaced. The cylinder is of 9j inches diameter and 12 inches 
stroke ; the firebox heating surface is 33^^ square feet ; the tube heating 
surface 139 square feet ; total heating surface 172i square feet ; the fire-grate- 
area 6i square feet ; the normal speed of the engine 150 revolutions per minute ; 
corresponding speed of the wire rope 2 J miles per hour; corresponding speeds 
of the road motion 2j and Ij miles per hour; diameter of the travelling or 
driving wheels 5j feet ; width of tires 14 inches ; capacity of water-tank 
135 gallons; capacity of coal-bunker 10 cubic feet; and weight of the engine 
in complete working trim 12i- tons. At Stafford, the indicator showed a 
maximum of 63J-horse-power exerted by this nominally 8-horse single- 
cyHnder engine. The boiler is made of steel, as well as all the principal 
working parts ; and the design and workmanship are of the same massive and' 
excellent character ob.served in all the machinery of Messrs. Fowler. 1'lie set 
is completely self-transporting. When \vorking with the engine and anchor 
shifting ground upon opposite headlands, the rope is required to be three 
times the length of the field, one length being always upon the drums. 
A special facility of the double-drum engine and anchor tackle, however, is 
that it can be worked also upon the stationary-engine system, which is advan- 
tageous in some situations. Fig. 11 is a i)lan of both arrangements. The 
travelling anchor is common to both modes of working ; but, when the engine 
is stationary, one snatch-block, S, with claw anchor, is shifted by hand in the- 
usual manner. It will be observed that there is no detached windlass to be 
transported, set down, and taken up, with exact placing and pinning down in, 
position, as in the ordinary " roundabout " system. Engine and windlass are- 
combined, or " self-contained," and the drums are self-coiling ; so that to man 
the tackle for stationary-engine work requires one engineman, one ploughman, 
two anchormen^ — in all four men — and two i^orter-boys. This is one extra 
hand beyond those employed when the engine moves along the headland. One 
drawback that should be mentioned is, that the position of the rope-drum 
near to the firebox, F, restricts the ability to run olf the rope in one angular 
direction. Thus, while the engine can freely work the implement in the 
direction of the dotted line A, it is unable to work in the direction of the 
dotted line G, in consequence of the rope from one drum coming in contact 
with the corner of the firebox. Hence there would be a difficulty in dealing 
with some fields; while in working at right angles (as in the Fig. ll)- 
great care has to be taken in kcejiing the engine well forward, or somewhat in 
advance of the line of furrow. For stationary working, the engine is planted 
