34 [2] 
from the passine; ice, when they happen to be lidinj^ witli a scope of 
sixty fiitlionis ])arallel to tlie breukwater. 
The nieai) depth in the harboi*, at low water, will be x!l feet. 
As this work will not be cxjjosed to a violent sea from any direc- 
tion, it is considered sufficient to make the base of each slope equal 
to twice the altitude. 
5th. Estimate of the Expense of a Breakwater. 
1st. As to a complete baibor at the position B. 
In the left flank of the breakwater, there will be, 
5,817,975 cubic feet. 
In the centre of do. 11,346,420 do. 
In the right flank do. 9,744,251 do. 
Total, 26,908,646 cubic feet. 
26,908,646 cubic feet equal to 996,616.52 cubic yards. 
One perch, or 24.75 cubic feet, at S2 GO, is 2.1818 per cubic yard; 
996,616.52 cubic yards of stone, pi-omiscuously thrown into form 
the mass, each stone weighing fiom 2 to 4 tons; for materials a»id 
labor, at S2.I8I8 per cubic yard, 2,174,417 92 
Add for unforeseen expenses 7 ^er centum, 152,209 25 
Total expense af complete breakwater, S2, 326, 627 17 
2d. As to the expense of a partial harbor at the position A. 
In the whole of the line of bieakwater there will be 2,585,536 
cubic feet, or 95,760.592 cubic yards. 
One perch, or 24.75 cubic feet, at §2, is S2.18 18 per cubic yard; 
95,7 60.592 cubic yards of stone, promiscuously thrown in to form 
the mass, each stone weighing. fiom § to 4 tons; for materials and 
labor, at §2.1818 per cubic yard, 208,930 46 
Add for unforeseen expenses 5 per cent. 10,446 52 
Cost of breakwater, §219,376 98 
Add for mooi'ings: 
12 cast ii'on anchors, each of 30cwt. at S70 
per ton, 1,260 00 
12 chain cables, of 12 fathoms each, of li 
inch iron; at one end of eacli cliain a ling, 
of 12 incl)es diameter in the clear, to be 
made of 2 inch iron, to receive the end 
of the vessel's cable, which I'ings should 
bepudt-eiied = 144 fathoms, at glO 50 per 
fathom, 1,512 00 
12 buoys for the chains, say at $20, 360 00 
3,132 00 
Total expense of partial breakwater and moorings, S222,508 98 
