The cost of a foreman is not included in this, as the contractor looked after the men himself.
Waterproofing.—The waterproofing of the structure proved a serious problem. It was thought at first that the concrete itself would be nearly water tight, but the tank leaked like a sieve. After considering several methods, an agent of a European waterproofing mixture prevailed upon those interested to try his compound. To apply it, the walls had to be dry, so a large coal burning stove was put in the reservoir and a fire kept up day and night. While this drying process was going on several light falls of snow occurred, and this had to be cleared away to make the walls and roof dry. Two coats of the mixture were applied according to the agent's instructions, and the reservoir was tested. The water fell nearly half a foot in an hour's time.
Then a waterproofing contractor agreed to make the reservoir water tight with paper and tar, by applying it on the inside. Three thicknesses of paper were laid on the bottom and run well up on the sides, each layer of paper being well covered with a preparation of tar. Upon testing it, it was found that the leaking had been reduced about 50 per cent. A preparation of asphalt was then placed over this, but upon a third test the tank still leaked. As the sub-contractor had verbally agreed to make it water tight for $125, only this amount was paid him. After this last test he refused to do any more work.
After these attempts the sides of the reservoir were exposed on the outside by excavating around it, and a one-brick-wall built up a few inches from the concrete. This space was filled in with rich cement mortar and the ground once more filled in around the structure. This work and the materials used in it cost $1,240. Upon a fourth test the reservoir was found to be water tight. Thus more than a third of the cost of the entire work was in waterproofing the structure, and this made the contract a money losing one, as this heavy cost was not anticipated.
Several items of miscellaneous work are listed in the total cost of the reservoir, such as filling in and puddling around reservoir and replacing cobble paving. The top of the structure was used as a bin for the storage of coal. For this purpose eight I-beams were embedded in concrete around the top to be used as posts for the sides of the bin. The cost of placing these is given.
Total Cost.—The cost of the structure without any profits was:
| 579 cu. yds. excavation @ $.896 | $ 529.65 |
| Steel | 395.00 |
| Crushed stone | 148.80 |
| Gravel | 4.00 |
| Sand | 50.40 |
| Cement | 123.20 |
| Lumber | 153.60 |
| Labor on forms | 200.09 |
| Labor on concrete | 203.35 |
| Plastering | 6.60 |
| Sides and bottom | 9.10 |
| Nails, wire, etc. | 4.98 |
| Bailing water | 21.19 |
| Building temporary fence | 1.65 |
| Extra excavation for forms, footings, etc. | 13.90 |
| Setting I-beams in concrete | 17.65 |
| Filling in and pudding around reservoir | 34.47 |
| Replacing cobble paving | 4.30 |
| Hauling tools | 3.60 |
| Heating reservoir and handling snow | 14.50 |
| Waterproof mixture | 29.00 |
| Labor applying it | 9.74 |
| Applying paper and tar, labor and materials | 125.00 |
| Labor and materials of final waterproofing | 1,240.00 |
| Tools | 48.75 |
| General expense | 210.00 |
| ———— | |
| Total | $3,602.52 |
COVERED RESERVOIR, AT FORT MEADE, SOUTH DAKOTA.—The following account of the method and cost of constructing a 500,000-gallon reservoir is compiled from information furnished by Mr. Samuel H. Lea, M. Am. Soc. C. E. As shown by Fig. 277, the reservoir consists of two equal compartments, each 50×60 ft. inside dimensions, with rounded corners. Both compartments are covered with a 3-in. slab roof carried on the walls and interior columns.
The concrete was a 1-2-4 Portland cement, sand and broken stone mixture, mixed by hand on a movable platform. A concrete gang consisted of four men who were each paid $2.75 per day. They wheeled the materials from the supply piles to the mixing platform, mixed the concrete and deposited it in place. During the construction of the footings and floor two concrete gangs were employed, but after the walls were started, one gang only was required for concrete work; the other gang was then put to work assisting the carpenters.
