| Materials. | Total. | Per cu. yd. |
| 126 bbls. cement at $2.75 | $346.50 | $3.893 |
| 88.9 cu. yds. screenings at $1.10 | 97.79 | 1.098 |
| 40.1 cu. yds. sand at $0.45 | 18.04 | 0.203 |
| 5 gals. oil at $0.65 | 3.25 | 0.036 |
| ——— | ——— | |
| Total materials | $465.58 | $5.230 |
| Labor. | ||
| 1,000 hrs. labor at $0.125 | $125.00 | $1.404 |
| Watchman | 29.15 | 0.327 |
| Labor cutting wood for fuel | 23.80 | 0.267 |
| Superintendence | 42.66 | 0.480 |
| ——— | ——— | |
| Total labor | $220.61 | $2.478 |
| Total labor and materials | $686.19 | $7.708 |
Fig. 79.—Details of Toe Blocks for Footing, Marquette Breakwater.
Molding Concrete Prism in Place.—The concrete prism was molded in alternate sections 10 ft. long; the form for the isolated sections consisted of eight pieces so constructed that when assembled in place and secured with bolts and turnbuckles the form was self-contained as to strength and required no outside support or bracing. The form once in place, all that remained to be done was to fill it, the block with the gallery through it being molded in one operation. The forms for the connecting blocks consisted of two slope panels, a panel for the harbor face and the gallery form, the blocks previously molded making the other sides of the form. The concrete was mixed by hand on shore, conveyed to the work in 1 cu. yd. cars and shoveled into the forms, where it was rammed with 35-lb. rammers. The following record covers 1,231 cu. yds. of concrete prism. In this concrete some 214 cu. yds. of rubble stone were embedded. The costs given are as follows:
| Materials— | Total. | Per cu. yd. |
| 1,780 bbls. natural cement at $1.068 | $1,901.04 | $1.545 |
| 963½ cu. yds. stone at $1.619 | 1,559.91 | 1.267 |
| 53½ cu. yds. screenings at $0.392 | 20.97 | 0.017 |
| 485.6 cu. yds. sand at $0.392 | 190.36 | 0.154 |
| Miscellaneous materials | 78.15 | 0.063 |
| ———— | ——— | |
| Totals | $3,750.43 | $3.046 |
| Labor Mixing— | ||
| 254 hrs. master laborer at $0.21⅞ | $55.56 | $0.045 |
| 4,470 hrs. labor at $0.175 | 782.42 | 0.635 |
| Superintendence | 18.20 | 0.015 |
| ———— | ——— | |
| Total labor mixing | $ 856.18 | $0.695 |
| Labor Transporting and Placing— | ||
| 35 days overseer at $2.33⅓ | $81.67 | $0.066 |
| 1,949 hrs. labor at $0.175 | 342.07 | 0.277 |
| Superintendence | 34.98 | 0.028 |
| ——— — | ——— | |
| Total labor transporting and placing | $ 458.72 | $0.371 |
| Grand total, labor | $1,314.90 | 1.066 |
| Total labor and materials | $5,065.33 | 4.112 |
No charge is made under materials for rubble stone as the only cost for this was cost of handling and this is included in transporting and placing.
BREAKWATER, BUFFALO, N. Y.—The following methods and costs of mixing and placing some 2,561 cu. yds. of concrete are given by Mr. Emile Low, for 10 parapet wall sections and 17 parapet deck sections for a breakwater at Buffalo, N. Y.
The concrete used was a 1 cement, 1 gravel, 1 sand grit and 4 unscreened broken stone. One bag of cement was assumed to measure 0.9 cu. ft. The voids in the sand grit and gravel were 27 per cent. and in the unscreened stone 39 per cent. The hardened concrete weighed 152 lbs. per cu. ft.
Fig. 80.—Sketch Plan of Concrete Mixing Plant for Buffalo Breakwater.