THE BATTLE TRACTOR, 1888.




The motive power was steam, and two separate engines, fed by one boiler, were used, one to drive each track ; apparently provision was made, if desired, for the crankshafts of these engines to be clutched together. Each track consisted of two endless belts, an inner and an outer; the outer belt, that which impinges on the ground, was composed of shoes arranged transversely and coupled together. Between the outer belt and the rollers ran the inner belt. The inner belt or link was of much less width than the outer and thus allowed the latter to swivel and adapt itself to irregularities of the ground, whilst the working of the rollers was not interfered with. A system almost identical with this one has recently been adopted for tank tracks.
The rollers were alternately flanged and plain, as on tanks. Two tails for steering and balancing the machine were fitted; a similar idea was adopted on Mark I machines and gun carriers, but subsequently discarded.
The general introduction of the internal-combustion engine and petrol as a fuel gave a further impetus to the tracked machine. In 1900 Frank Bramond patented a track which could be applied to pneumatic-tyred vehicles, either to single wheels or to two pairs of wheels. In 1907 a Rochet-Schneider was fitted with a track by Roberts and tested at Aldershot. This car was exhibited together with a 70 h.p. Horusby chain-track tractor and took part in the Royal Review at Aldershot in May 1908. This same year Hornsby fitted up a 75 h.p. Mercedes motor-car with a track to demonstrate its advantages for high-speed work on sand. " This car was run daily for five months at Skegness, on loose sand, and it is understood that a speed of twenty miles an hour was obtained."