238 
THE SMOKE ABATEMENT EXHIBITION. 
forward is taken by an india-rubber buffer. The cam-wkeel ha& 
three different lifts or throws, so that the coal is sent to three 
different parts of the lire and is thereby spread uniformly over 
it. This, as far as smoke consuming is concerned, is a mistake, 
because green fuel is fed on to the back of the furnace as well 
as the front. 
The Helix Furnace Feeder Company supply coal to the 
furnace by means of two augur-like screws, which take the place 
of some of the fire-bars, and by turning in a chamber which is 
only open at the top, cause the coal to travel along and up into 
the lire, thereby supplying the fuel at the bottom of the live 
coal. It possesses the advantage too, in common with several 
other forms, that hand stoking can be at once resorted to if the 
mechanical means should fail. 
In McHougall’s Mechanical Stoker the fuel is pushed forward 
by a ram furnished with a reciprocating movement. 
In Newton’s Mechanical Stoker the fuel is forced on to the 
grate by means of a blast of hot air. The air pipes are led along 
the side of the boiler, the air thereby becomes heated, and it then 
blows the coal which has been previously crushed on to the bars. 
In these various classes of Mechanical Stokers, the w^aste of 
fuel, owing to the cooling of the furnace, that arises from the 
entrcJiice of cold air into the lire every time the furnace door is 
opened, is avoided. But it has to be remembered that a certain 
amount of power is required to drive the machinery which feeds 
the lire, and tliis has to be taken into account in estimating the 
economy of the machine, and the complication of parts in many 
of them is a serious objection also. 
Another extremely interesting exhibit is that shown by the 
Great Britain Smoke-Consuming and Fuel-Saving Company. 
A jet of steam passes over the top of a pipe through which air 
is supplied, and by this means a forced draught is obtained, and 
air is sent into the furnace and burns the smoke. 
