234 
THE SMOKE ABATEMENT EXHIBITION. 
The handle, when pushed back, causes the rake-bars to return 
to their old position. 
McMillan’s grate has underneath it a box hinged about a 
horizontal axis, the section at right angles to which is of the 
form of a sector of a circle. When the fire is required to be 
replenished, the box is pulled out, the contents of the grate 
meanwhile resting on a plate fixed to the back of the box. The 
box is filled and replaced, and the coals are then forced up by 
lifting a moveable bottom. 
Besides these and many others of a similar kind, an 
invention of W. S. Melville’s, called a “Smoke Abater Shovel,” 
may be noticed. It has for its object the introduction of coal 
beneath the fire in an ordinary grate. The shovel is of 
rectangular section, closed on all sides, and having on the top 
towards the front a hinged lid. When the lid is filled with 
coals and shut, it is, in front, of the shape of a wedge, so that it 
can be readily introduced under the contents of the grate. 
When this is done, a slide on the handle opens the lid, the 
piston may be pushed forward, and the green coals deposited 
under the live coals in the fire. This shovel is very useful for 
ordinary grates. 
Engert’s grate belongs to another kind of stove, in which the 
fuel is stored in a box or boxes at the side of, or behind, the fire, 
so that the coal is gradually coked, and the hydrocarbon evolved 
and consumed in passing through the fire. 
Another plan is to make the capacity of the grate sufiicient 
for a day’s consumption, the coal being lighted on the top, and 
gradually burning downwards. In Edwards’s grate this is 
effected by having a balanced shutter, which separates the burnt 
from the unburnt fuel. As the fuel burns away the shutter 
is pushed down, and so, if the grate is filled once, a store of 
coals is obtained sufficient for a whole day’s consumption. This 
grate has already been introduced into Guy’s and other hospitals. 
