and Miscellaneous Implements at Bnsfol. 1-9 
pressed air, heated by combustion, is here also the source of power ; but instead 
of petroleum, gas is used. The gas is drawn into the air-pump with the air, 
and the mixture is compressed together, and in this state admitted into the 
working cylinder, where it is fired by a permanent flame, burning in the inlet 
orifice. In this engine the heat of combustion is not wasted, but serves in the 
first instance to heat a water-jacket round the cylinder, through which the 
water is [>umped into a small field tubular-boiler, where it is converted into 
steam by the heat of the exhausted gases, and the steam so generated is ad- 
mitted into the working cylinder, and mixes then with the gas. This admix- 
ture of steam, besides conducing very materially to economy of working, is 
said to increase the durability of the working parts, and render very little 
lubrication necessary. The various valves are actuated by cam motions, and, 
like the hydrocarbon engine, the mechanism appears complicated, though it 
really is not so. 
Amongst the novelties of the Bristol Meeting was a tipping 
waggon, shown by Frank P. Milford, of Kenn, Exeter, con- 
structed to carry G tons. The material and workmanship are 
highly creditable. The bed-framing of the body and also the 
bottom-boards are of oak, the sides and shelvings (the latter 
over the wheels) consist of li-inch elm planks, well stayed with 
iron, and firmly bolted together. Capacity, 11 ft. 6 in by 4 ft. 4 in. 
by 1 ft. 5 in. clear of the body ; shelvings, 11 in. wide each side ; 
area of curved ladders 18 ft. 6 in. wide, by 3 ft. deep. The 
object of this construction is to enable the waggon to carry a large 
quantity of corn, hay, or straw, without the necessity for ropes, 
as the farther the load is carried the tighter it gets. The tipping 
apparatus consists of an oak framing, fitted between the framing 
of the bed ; consequently, no additional height of body is re- 
quired. The front and back body pillars are bolted and fitted 
to the tip-frame, the front pillars taking the front carriage at the 
main pin (the pin from which the carriage locks under) and the 
hind pillar taking the hind axle and case. The framing is so 
strongly inade that it is impossible for it to shift or get out of 
place. 
In the front part of the bottom of the waggon, and directly 
behind the front carriage, is a hole 12 in. by 24 in., through which 
the front part of the load empties itself. This hole is covered 
by a hinged door, which is held up by a pin ; when this is 
knocked away, it follows that the fore part of the load is dis- 
charged, and the weight of the tail causes the waggon to tip and 
discharge the rest of the load. The horses are moved on, and 
the body gradually resumes its proper place. This is a clever 
arrangement, very suitable for the discharge of coals, lime, stone, 
or even roots. The tailboard is hinged, and when thrown back 
IS held up by a spring so as to be out of the way. The hind- 
wheels are placed well forward, which materially aids the tipping. 
A trial was made with a load of coals, which were discharged in 
a lew minutes — certainly in much less time than if they had 
VOL. XV. — S. S. K 
