Thus a litre of gunpowder weighs about 2 lbs.; it produces, by burning,
about 400 litres of gas; this gas, liberated, and under the action of a
temperature of 2,400°, occupies the space of 4,000 litres. Therefore the
volume of powder is to the volume of gas produced by its deflagration as
1 to 400. The frightful force of this gas, when it is compressed into a
space 4,000 times too small, may be imagined.

This is what the members of the committee knew perfectly when, the next
day, they began their sitting. Major Elphinstone opened the debate.

"My dear comrades," said the distinguished chemist, "I am going to begin
with some unexceptionable figures, which will serve as a basis for our
calculation. The 24-lb. cannon-ball, of which the Hon. J.T. Maston spoke
the day before yesterday, is driven out of the cannon by 16 lbs. of
powder only."

"You are certain of your figures?" asked Barbicane.

"Absolutely certain," answered the major. "The Armstrong cannon only
uses 75 lbs. of powder for a projectile of 800 lbs., and the Rodman
Columbiad only expends 160 lbs. of powder to send its half-ton bullet
six miles. These facts cannot be doubted, for I found them myself in the
reports of the Committee of Artillery."

"That is certain," answered the general.

"Well," resumed the major, "the conclusion to be drawn from these
figures is that the quantity of powder does not augment with the weight
of the shot; in fact, if a shot of 24 lbs. took 16 lbs. of powder, and,
in other terms, if in ordinary cannons a quantity of powder weighing