64 Modern Cannon Powder. (January, 
The pellet form was recommended principally as a con- 
venient method of making a large grain powder of consider- 
able uniformity in size and density ; but the Committee did 
not consider that the subject of gunpowder had been ex- 
hausted by them, and closed their Report with a recom- 
mendation that ‘‘ systematic artillery experiments should be 
instituted with this pellet powder, of a sufficiently compre- 
hensive character to test thoroughly the system.” 
In the meantime, while the labours of this Committee 
were still progressing, other experiments were being carried 
on in this country. In 1863-4 a proposal was made to press 
granulated powder into discs the size of the bore of the 
gun, and perforated with holes to facilitate the passage of 
the gas. These discs varied in thickness from 2 to 3 inches, 
and were made of powder of various-sized grains, the amount 
of the compressing force differing in different specimens. 
The results of these trials were not sufficiently satisfactory 
to lead to the adoption of this form of powder. About the 
same time a similar description of powder, proposed by 
Dr. Doremus, an American, was tried unsuccessfully, both 
in America and in this country; and again, in 1866, discs— 
made by compressing the powder meal—gave even less 
satisfactory results. 
The Americans, about this period, introduced an irregular 
large grain powder, which they called ‘‘ Mammoth,” and 
still use in the large charges fired from their enormous cast- 
iron smooth-bored guns, to which they obstinately ad- 
hered for years after the remainder of the civilised world 
had been armed with rifled ordnance of wrought-iron or 
steel. The size of this powder ranges from o'15 inch to 
0°30 inch, and its density is very moderate, being 1°70 to 1°75. 
‘‘ Prismatic”? powder appears, also, to have been tried in 
America in 1865; it had already been fired with good results 
from the heavy steel breech-loading guns which the Russians 
and Prussians have obtained from Messrs. Krupp, of Essen. 
This powder is shown at Fig. 2, Plate I., being made in the 
form of regular hexagonal prisms about 1 inch thick and 
o’8 inch in the side, perforated with seven holes about 
o'r inch in diameter. In making up charges of this powder, 
the prisms are built up regularly in the cartridge bags, like 
honey-comb, which are then tightly tied at the mouth, so 
that the grains are kept firmly in their place. The perfora- 
tions thus form long tubes through the charge, by which the 
gas permeates the whole mass. 
The powder meal is pressed into the shape of these prisms 
in a very moist state, but the pressure is not great, as the 
