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city did not fail to prescribe the best remedy by rules in- 
tended to reduce to a minimum the external opening. He 
directed that the throat should be no larger than necessary 
to receive the muzzle of the gun and to endure the shock of 
its discharge, that it should not be more than two feet from 
the exterior surface of the wall, that the cheeks should be 
parallel to the sides of the sector of fire ; and to render prac- 
ticable these arrangements, he invented the “affut @ atguille” 
(carriage with tongue), which has served as the type of nearly 
all subsequent casemate gun-carriages. It is strange, that, 
even while adopting the plans of Montalembert, Euro- 
pean engineers should have almost wholly overlooked these 
Maxims, and that it was reserved for our own illustrious 
engineer to make their application, and, in perfecting the 
casemate and the embrasure, to become a co-worker with 
Montalembert, by bringing the casemated water-battery to 
its highest degree of perfection. 
I now revert to General Totten’s labors in this connection, 
and in reference thereto I quote from his report to the 
Secretary of War :— 
“The first casemated battery was completed in 1808. It 
has two tiers of guns in casemates, and one in barbette. 
The exterior openings of the lower embrasures are 4’ 8” by 
6 feet, giving an area of 28 square feet; and of the second 
tier, 3/ 8” by 5 feet, area 183 square feet, the horizontal 
traverse of the guns being limited to 44 degrees. 
“Within three or four years of the time just mentioned 
two other casemated batteries were built, each having @ 
Single tier of guns in casemates, with exterior openings 
of 4’ 5” by 5 feet, area 22 square feet; one with horizontal 
Scope of about 42 degrees, and the other of about 45 de- 
grees, 
“In 1815 the author of this report was called on to pre- 
