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the arches, their thickness and manner of covering, SO as 
to obtain perfect drainage and to avoid the injurious ef- 
fects of frost, &c., were problems of prolonged research and 
skilful solution, establishing for General Totten the right.to 
be considered the author of the American casemate. 
In connection with these researches may be mentioned 
those also which were directed to the determination of the 
manner of mounting guns “en barbette.”* As the dimen- 
sions of sea-coast ordnance increased, more and more elab- 
orate structures became necessary for their mounting and 
management. The planning and construction of the car 
riages belonged to the Ordnance Bureau, but it was General 
Totten’s task to adapt the platforms and parapets thereto- 
None but the engineer or artillerist can thoroughly under- 
stand the difficulty and complexity of the problems therein 
involved. To provide a platform which shall support, with- 
out the slightest deflexion, the weight, and resist the shock 
of discharge, while it provides for the training or pointing 
of the gun, — which is so adapted to the parapet as to allow 
the maximum horizontal sector of fire and to afford the 
most perfect cover to the gunners consistent with allowing 
all the depression demanded by the circumstances of the 
ease, — such are the conditions to be fulfilled, separately, for 
each calibre of gun. After years of experience, and ‘after 
our sea-coast ordnance had attained its highest development 
prior to the introduction of the rifled gun and fifteen-inch 
columbiad, General Totten embodied his results in a litho- 
graphic sheet exhibiting to the eye of the engineer for every 
kind of gun and for every probable case the particular 50 
lution. This single sheet exhibits strikingly the characteris- 
ties of the author’s mind,—the profound study which he 
brought to bear on every subject, the scrupulous accuracy 
_ * A barbette gun is one which is fired over a parapet. 
