EULOGY ON THE LATE GENERAL JOSEPH G. TOTTEN. 289 



" Fourth, a wrought iron plate of half an inch in thickness is adequate to pro- 

 tect the outer margins and the offsets of embrasures from injury by grape or 

 <;an ; ster shot." 



These facts established, the effect of the form and dimensions of the embra- 

 sures in carrying in the smaller missiles was investigated ; the recorded results 

 will enable us to appreciate the force of Montalembert's expression, " murderous 

 funnels," as even its author could not do. 



" Suppose a hundred-gun ship to be placed within good canister 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 battery. 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 dis- 

 charges 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 distauce, is a large al- 

 lowance, 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 6^ balls. 



41 Or within the exterior opening of one of the embrasures of our 

 second target, of which the area is S.9 square feet, there would 

 fall 58 balls. 



* Within the European embrasure above mentioned, having fifty- 

 four square feet of opening,* there would be received in half an 

 hour 351 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 thousand 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 General Totten's embrasure of IS 15, which 

 is but little larger than that of the second target, is to the European one, and 

 how thoroughly he had, at that early day, mastered the subject. He had, in- 

 deed, perfected the embrasure so far as it could be done with masonry alone. 



But the quantity of small missiles which even that embrasure would receive 

 is dangerously great, and would be much diminished if the funnel-form of the 

 mouth could be done away with, and the throat reduced to an absolute minimum. 

 This could be accomplished only by the use of iron, and the conclusions I have 

 just quoted furnish the data necessary to its successful application. 



The throat (still placed two feet back from the outer face of the wall) being 

 formed of iron plates, it became practicable to cut away the flaring surfaces of 

 masonry, so as to present others parallel or perpendicular to the face of the wall, 

 and by this change of form to exclude all missiles not directed within the limits 

 of the throat itself. Still more completely to accomplish the object, wrought- 

 iron shutters of two inches thickness (as determined by the experiments) were 

 applied, by which, except at the moments of aiming and firing, the embrasure 

 was entirely closed. 



Such is the history of the casemated battery and casemated embrasure in the 

 United States. We have seen that the perfection to which they have been 

 brought is clue to General Totten, and to General Totten alone. Nor is it to the 

 experiments which I have been describing, laborious, skilful, and thorough as 

 they were, that we may solely attribute such results. We must look back to 



* Reference is made to the embrasure of a European work built within the last twenty- 

 five years. 



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