ation.

About 1750, the French mortar had a bore length 1-1/2 diameters of the
shell; in England, the bore was 2 diameters for the smaller calibers
and 3 for the 10- and 13-inchers. The extra length added a great deal
of weight to the English mortars: the 13-inch weighed 25
hundredweight, while the French equivalent weighed only about half
that much. Mueller complained that mortar designers slavishly copied
what they saw in other guns. For instance, he said, the reinforce was
unnecessary; it "... overloads the Mortar with a heap of useless
metal, and that in a place where the least strength is required, yet
as if this unnecessary metal was not sufficient, they add a great
projection at the mouth, which serves to no other purpose than to make
the Mortar top-heavy. The mouldings are likewise jumbled together,
without any taste or method, tho' they are taken from architecture."
Field mortars in use during Mueller's time included 4.6-, 5.8-, 8-,
10-, and 13-inch "land" mortars and 10- and 13-inch "sea" mortars.
Mueller, of course, redesigned them.

[Illustration: Figure 39--COEHORN MORTAR. The British General
Oglethorpe used 20 coehorns in his 1740 bombardment of St. Augustine.
These small mortars were also used extensively during the War Between
the States.]

The small mortars called coehorns (fig. 39) were invented by the famed
Dutch military engineer, Baron van Menno Coehoorn, and used by him in
1673 to the great discomfit of French garrisons. Oglethorpe had many
of them in his 1740 bombardment of St. Augustine when the Spanish,
trying to translate coehorn into their own tongue, called them
_cuernos de vaca_--"cow horns." They continued in use through the U.
S. Civil War, and some of them may still be seen in the battlefield
parks today.

Bombs and carcasses were usual for mortar firing, but stone
projectiles remained in use as late as 1800 for the pedrero class
(fig. 43). Mortar projectiles were quite formidable; even in the
sixteenth century missiles weighing 100 or more pounds were not
uncommon, and the 13-inch mortar of 1860 fired a 200-pound shell. The
larger projectiles had to be whipped up to the muzzle with block and
tackle.

[Illustration: Figure 40--THE "DICTATOR." This huge 13-inch mortar was
used by the Federal artillery in the bombardment of Petersburg, Va.,
1864-65.]

In the last century, the bronze mortars metamorphosed into the great
cast-iron mortars, such as "The Dictator," that mammoth Federal