Messrs Bur stall and Hill’s Steam Carriage. 351 
riage to be moved forward or backward. To the fore naves 
are fixed two cylindrical metal rings, round which are two fric- 
tion-bands, to be tightened by a lever convenient for the foot 
of the conductor, and which will readily retard or stop the coach 
when descending hills. K is the seat of the conductor, with 
the steering-wheel L in front, which is fast on the small up- 
right shaft 1, and turns the two bevil pinions 2 ; and the shaft 
3, with its small pinion 4, which, working into a rack on the 
segment of a circle on the fore carriage, give full power to place 
the two axles at any angle necessary for causing the carriage to 
turn on the road, the centre of motion being the perch-pin * I. 
The fore and hind carriage are connected together by the 
perch 5, which is bolted fast at one end by the fork, as seen 
at Fig. and at the other end is secured by two collars, which 
permit the fore and hind wheels to adapt themselves to the 
twist of the road. 
To ascend steep parts of the road, and particularly when the 
carriage is used on railways, or to drag another behind it, great- 
er friction will be required on the road than the two hind wheels 
will give, and there is therefore a contrivance to turn all the four 
wheels. This is done by the pair of mitre wheels 4, one being 
on the hind axle, and the other on the longitudinal shaft 6, 
on which shaft is a universal joint directly under the perch-pin 
*1 at 7. This enables the small shaft 7. to be turned though 
the carriage should be on the lock. On one end of the shaft 
7. is one of a pair of bevil wheels, the other being on the fore- 
axle ; which wheels are .in the same proportion to one another 
as the fore and hind wheels of the carriage are, and this causes 
their circumference to move on the ground at the same speed. 
Fig, 6. is a ground plan, and Fig. 7. a section of another 
way of impelling all the wheels together, where the perch-pin 
is over the centre of the axle, 8. is a wheel turning upon 
it, which being put in motion by the wheel 9, will cause it, 
by means of the wheel 10, to turn the fore-axle, and there- 
by the wheels. 
There are safety-valves and cocks to admit, shut off, and 
regulate the steam, &c. But as the engraving is necessarily on 
a small scale, and such things are familiar to mechanicians, we 
have thought it unnecessary to cumber our account with them. 
a a £ 
