The cost of these 9,614.4 cu. yds. of concrete in place was:
| Hand Mixed and Placed by Derrick— | Per cu. yd. |
| Labor mixing 1,777 cu. yds | $1,072 |
| Repairs, fuel, etc | 0.016 |
| ——— | |
| Total cost mixing | $1,088 |
| Labor placing 2,372 cu. yds. | 0.6025 |
| Fuel, tramways, etc. | 0.1958 |
| ——— | |
| Total cost placing | $0.7983 |
| Machine Mixed and Placed by Chute— | |
| Labor mixing 7,837 cu. yds. | $0.388 |
| Repairs, fuel, etc | 0.046 |
| ——— | |
| Total cost mixing | $0.434 |
| Labor placing 7,242 cu. yds | 0.414 |
| Fuel, tramways, etc. | 0.045 |
| ——— | |
| Total cost placing | $0.459 |
| Materials and Supplies 9,614 cu. yds.— | |
| Timbering | $0.145 |
| Cement | 3.289 |
| Sand and gravel | 1.073 |
| Broken stone | 0.536 |
| Cement testing, repairs, etc. | 0.223 |
| ——— | |
| Total | $5,266 |
| Plant and Superintendence, 9,614 Cu. Yds.— | |
| Engineering, superintendence, repairs, etc. | $1,508 |
| 20% cost of plant | 0.165 |
| ——— | |
| Total | $1,673 |
The comparative cost of hand and machine mixing and handling was thus:
| Item— | Hand. | Machine. |
| Mixing per cu. yd. | $1.088 | $0.434 |
| Placing per cu. yd. | 0.798 | 0.459 |
| Materials, etc., per cu. yd. | 5.466 | 5.466 |
| Plant, etc., per cu. yd. | 1.673 | 1.right |
| ——— | ——— | |
| Totals | $9.025 | $8.032 |
The average total costs of all the concrete placed were:
| Mixing per cu. yd. | $0.555 |
| Placing per cu. yd. | 0.543 |
| Materials per cu. yd. | 5.266 |
| Plant, etc., per cu. yd. | 1.673 |
| ——— | |
| Total | $8.037 |
LOCKS, COOSA RIVER, ALABAMA.—The following methods and costs are given by Mr. Charles Firth for constructing lock No. 31 for the Coosa River canalization, Alabama. This lock is 420 ft. long over all, 322 ft. between quoins, 52 ft. clear width, 14.7 ft. lift and 8 ft. depth of water on sills; it contained 20,000 cu. yds. of concrete requiring 21,500 bbls. cement, half Alsen and half Atlas.