Materials and Labor.

3 Coats Hard

Finish.

Two Coats slipped.

4 casks.

3½ casks.

Lump lime..

2/3 "

Plast. Paris..

½ "

Laths........

2000.

2000.

Hair...........

4 bush.

3 bush.

Sand.........

7 loads.

6 loads.

Materials and Labor.

3 Coats Hard

Finish.

Coats

Sipped.

White sand..

2½ bush.

Nails..........

13 lbs.

13 lbs.

Masons.......

4 days.

31 days.

Laborer.......

3 "

2 "

Cartage.........

1 "

3/4 "

Hydraulic

1½ parts unslacked hydraulic lime, 1½ parts sand, 1 part gravel, and 2 parts of a hard broken limestone.

This mass contracts one-fifth in volume. Fat lime may be mixed with concrete without serious prejudice to its hydraulic energy.

Various Compositions Of Concrete

Forts Richmond and Tompkins, U. S.

Hydraulic

308 lbs. cement = 3.65 to 3.7 cubic feet of stiff paste. 12 cubic feet of loose sand = 9.75 cubic feet of dense.

For Superstructure

11.75 cubic feet of mortar as above, and 16 cubic feet of stone fragments.

In the foundations of Fort Tompkins, about 1/12 of its volume was composed of stones from ¼ to ¾ of a cubic foot in volume, rammed into the wall as the concrete was laid.

Sea Wall. Boston Harbor. Hydraulic

308 lbs. cement, 8 cubic feet of sand, and 30 cubic feet of gravel. The whole producing 32.3 cubic feet.

Superstructure

308 lbs. cement, 80 lbs. lime, and 14.6 cubic feet dense sands. The whole producing 12.825 cubic feet.

Cost of labor and materials expended in laying concrete foundation at Fort Tompkins, during the year 1849, per cubic yard as laid, $2.26.