of the mortar is called the _chamber_, which contains the powder. When
fired, the powder in the chamber not only sends the bomb, but at the
same time, sets fire to the fusee, which continues to burn slowly, as
it passes through the air, and the calculation always is, to have the
fire from the fusee reach the powder in the shell, _at the moment the
latter reaches the ground_. It then bursts, and the scattering
fragments of iron often do horrible execution."

_William_. "Did you say, father, that mortars Were _short_ guns?"

_Gen. P_. "Land mortars are quite short; sea mortars, or such as are
used on board vessels, are longer and heavier, because they are
usually fired at greater distances. A land mortar, which will throw a
shell thirteen inches in diameter, weighs thirteen hundred weight; the
weight of the shell is about one hundred and seventy-five pounds; it
contains between nine and ten pounds of powder; and is fired by means
of about the same quantity of powder."

_William_. "Pray, father, who invented bombs?"

_Gen. P_. "The inventor is not known; they have been in use since the
year 1634.

"Some years after the above affair, Crosby himself related the manner
in which the soldiers contrived to escape unhurt. When a shell rose in
the air, every one would stop working, and watch its course, to
ascertain whether it would fall near him. If it appeared to approach
so near, as to endanger any one, he would dodge behind something, till
it had burst, or passed by."