UTILIZATION OF THE FISH WASTE OF THE PACIFIC OCEAN. 31 
chamber of brickwork. Hot gases from crude petroleum burners are 
admitted to the chamber surrounding the cylinder and are drawn 
thence into the cylinder through apertures constructed at intervals in 
the walls. The scrap to be dried is admitted at the hot end of the 
cylinder and removed at the cool end, thus traveling with the current 
of air. From the cylinder it drops into an elevator and is carried 
therein directly to the bagging room. The current of gases through 
the drier is maintained by a rotary fan situated behind the drier. 
By means of this the gases drawn from the drier are forced through 
a chamber where they are washed free from suspended particles by 
means of a water spray. Thence they are driven through the fire box 
beneath the factorv boilers. In this manner odors arising from the 
hot-air drier, and constituting, perhaps, the only objection to its use, 
are completely destroyed. 
In the fertilizer plants of the Pacific coast the steam drier is em- 
ployed most commonly, owing possibly to the simplicity of its in- 
stallation and operation and to the fact that of all the driers it is 
most readily available in the desired capacities. It is not intended 
that the idea shall be conveyed by this statement that the steam drier 
inherently is more simply installed and operated. Such is not 
believed to be the case. But at present the hot-air driers advertised 
for sale and actually in use are large in both size and capacity and 
are unfit for the treatment of small amounts of material. The manu- 
facturers have failed to meet, or perhaps to create, a demand 
for driers of small capacity, and for that reason the steam drier is 
in most common use. An additional advantage possessed by the 
steam drier is its simplicity of regulation. Overheating being im- 
possible, it remains only to admit the steam and wait for the charge 
to dry. It can not be regarded as the most efficient or as the most 
economical except in cases where exhaust steam is employed. 
The type of steam drier found in use in clrjung scrap from salmon 
waste usually is a horizontal cylinder provided with steam coils in- 
side, or encircled hj a steam jacket. For stirring, the cylinder is 
equipped with paddles revolving in it, or the cylinder itself is 
rotated on a horizontal axis. 
A third type of drier, recently installed in a certain manufactory, 
is unique in that it makes use of the waste heat from the fires be- 
neath the factory boilers. As this drier was designed by the operator 
from ideas suggested by his experience, and is not advertised for sale 
by the manufacturers of driers, the writer does not feel justified 
in publishing here the details of its construction. It should suffice 
to say that the drier is reported as being quite efficient and satis- 
factory, and the scrap coming from it is of a ven 7 high quality. Its 
lack of importance as a type is more than made up by its value 
as an illustration of what is possible in the enhancement of economy 
in a fish-renderine: plant. 
