722 The Trials of 8 elf -binding Harvesters at Chester. 
being raised or lowered in curved guides securely attached to 
the main framing. Pinions fixed on the ends of the axle gear 
into racks formed on the curved guides, and the axle is turned 
by means of a worm wheel and worm, the spindle of the latter 
ending in a square at the rear of the machine, and being actuated 
by a handle which is shipped on, and is made to lock the spindle 
in any position. 
Fixed on the nave of the main wheel is a sprocket driving- 
wheel which actuates a second motion shaft, which crosses 
the machine in rear of the main wheel by means of a pitched 
chain which drives a pinion running loose on the shaft, and set 
into gear by being slid on to a pin fixed on the shaft, by means 
of a vertical rocking spindle fitted with a crank which is actuated 
by the driver by means of a handle formed on the upper end of 
the spindle, and placed within his reach. By this means the 
whole of the machinery can be started or stopped at pleasure. 
The frames which carry the main wheel are strongly braced. 
The third motion shaft, which runs fore and aft, is driven by 
bevel gear from the outer end of the second motion shaft, and 
terminates at its forward end in a disc which carries the crank 
by means of which the knife is actuated. 
The rear end of the crank-shaft carries a sprocket-wheel 
which drives a pitched chain, which passes in turn first over a 
sprocket-wheel, driving the main shaft of the binding me- 
chanism, next over a wheel keyed on the spindle of the top 
roller driving the lower elevating canvas, thirdly over a 
sprocket-wheel which drives the spindle, which actuates the 
reel and the buttor, and lastly over a sprocket-wheel which 
actuates the platform apron. The slack of the chain is taken 
up by an adjustable jockey-roller fixed to the main frame. 
The upper elevator canvas is driven from the top roller of 
the lower one by means of a pair of spur wheels. The rear 
end of the upper elevator is floating so that it can adjust itself 
to the weight of the crop. 
A roller is interposed between the top roller of the lower 
elevator and the upper edge of the binding platform in order 
to bridge over the space without unduly increasing the height 
of the elevators and imposing unnecessary work in raising the 
corn. This roller is driven through an idle wheel by a small 
spur wheel on the top roller spindle of the lower elevator. 
All the bearings are self-adjusting, the bushes having 
spherical enlargements about their middles which permit of 
sufficient motion to ensure the axles pressing uniformly all along 
their bearings. 
A board, some six inches high, crosses the rear of the grain 
