106 
“Suppose a hundred-gun ship to be placed within good can- 
ister range of a casemated battery of about the ship’s length 
and height, to the fifty guns of the ship’s broadside there would 
be opposed about twenty-four guns in two tiers in the bat- 
tery. The ship would fire each gun once in three minutes 
or ten times in half an hour ; the fifty guns would therefore 
make five hundred discharges within that time. 
“With one hundred and fifty-six balls in each thirty- 
two-pound canister (weighing in all thirty-one and a half 
pounds) there would be thrown seventy-eight thousand balls 
in thirty minutes. Supposing one half to miss the fort,— 
which, considering the size of the object, and the short dis- 
tance, is a large allowance, —there would still remain the 
number of thirty-nine thousand balls to strike a surface of 
(say) six thousand square feet, that is, — 
“On each square foot, . . : . 63 balls. 
“ Or within the exterior opening of one of the 
embrasures of our second target, of which 
the area is 8.9 square feet, there would 
Oh ee ee. se 
“Within the European embrasure above men- 
tioned, having fifty-four square feet of 
opening,* there would be received in half 
an how 35... a ; . 3851 balls.” 
And if the ship carried modern eight-inch guns, and fired 
canister of musket-balls, these figures would be in the three 
cases fifty-one, four hundred and fifty-three, and two thou- 
sand seven hundred and fifty-four. These theoretical con- 
clusions were verified by the experimental firing with grape 
and canister, and it is thus seen how greatly superior Gen- 
eral Totten’s embrasure of 1815, which is but little large? 
* Reference is made to the embrasure of an European work built 
within the last twenty-five years, 
