capacity of all the fire chambers and it should extend down about as low 
as the back end of the grate. The flue through which the products of 
ber. If the surfaces of this masonry were smooth the bagasse would lie 
against them in such a manner as to obstruct the upward radiation of the 
heat and the downward passage of the vapors. 
These corrugations are unnecessary in burning tan and sawdust. 
The spaces between the grate bars for burning bagasse should be about 
6 inches wide for the finest grinding and twenty inches for the coarsest, 
and should vary between these widths according to the fineness of grind- 
ing, but for sawdust and tan much less, say from one inch to 4 of an inch. 
The grate should be made of fire brick. . 
The operation of my furnace is as follows: A hot fire of dry fuel 1s 
kindled in the lower or fire chambers of the furnaces and after it has been 
continued till the masonry is well heated, the chamber above the grate 18 
fed with the begasse or other wet fuel. This hot fire in the fire chamber, 
especially towards the front of it under the principal mass of the wet fuel, 
must be preserved throughout the operation. The heat from the meee 
. ¢ bs 
and otherwise into the fire chamber and mixing chamber, Ww! 
posed, furnishing much oxygen to the fire, and supply the oxyge™ — 
sary to combustion of all the combustible gases issuing from me 
chamber, If by accident the fire in the lower part of the furnace 
predominate, the draught should be Rainched 
i ays the charred matter falling through the open ge will sup: 
_ ply its place; and the caloric thus produced by the com 
