piece
used against Petersburg, Va. Wrought-iron beds with a pair of rollers
were built for them. In spite of their high trajectory, mortars could
range well over a mile, as witness these figures for United States
mortars of the 1860's, firing at 45 deg. elevation:

_Ranges of U. S. Mortars in 1861_

Caliber Projectile Range
weight (pounds) (yards)

8-inch siege 45 1,837
10-inch siege 90 2,100
12-inch seacoast 200 4,625
13-inch seacoast 200 4,325

At the siege of Fort Pulaski in 1862, however, General Gillmore
complained that the mortars were highly inaccurate at mile-long range.
On this point, John Mueller would have nodded his head emphatically. A
hundred years before Gillmore's complaint, Mueller had argued that a
range of something less than 1,500 yards was ample for mortars or, for
that matter, all guns. "When the ranges are greater," said Mueller,
"they are so uncertain, and it is so difficult to judge how far the
shell falls short, or exceeds the distance of the object, that it
serves to no other purpose than to throw away the Powder and shell,
without being able to do any execution."

PETARDS

"Hoist with his own petard," an ancient phrase signifying that one's
carefully laid scheme has exploded, had truly graphic meaning in the
old days when everybody knew what a petard was. Since the petard fired
no projectile, it was hardly a gun. Roughly speaking, it was nothing
but an iron bucket full of gunpowder. The petardier would hang it on a
gate, something like hanging your hat on a nail, and blast the gate
open by firing the charge.

Small petards weighed about 50 pounds; the large ones, around 70
pounds. They had to be heavy enough to be effective, yet light enough
for a couple of men to lift up handily and hang on the target. The
bucket part was packed full of the powder mixture, then a
2-1/2-inch-thick board was bolted to the rim in order to keep the
powder in and the air out. An iron tube fuze was screwed into a small
hole in the back or side of the weapon. When all was ready, the
petardiers seized the two handles of the petard and carried it to the
troublesome door. Here they set a screw, hung the explosive instrument
upon it, lit the fuze, and "retired."

Petards were used frequently in King William's War of the 1680's to
force the gates of small German towns. But on a well-