Two parallel 8-in. brick walls 26 ft. long were built 4 ft. apart and 2½ ft. high to form a furnace. On these walls at one end was set a 4×6×2 ft. steel plate tar heating tank. Next to this tank for a space of 4×8 ft. the walls were spanned between with steel plates. This area was used for heating sand. Another space of 4×8 ft. was covered with 1½ in. steel rods arranged to form a grid; this space was used for heating the broken stones. The grid proved especially efficient, as it permitted the hot air to pass up through the stones, while a small cleaning door at the ground allowed the screenings which dropped through the grid to be raked out and added to the mixture. A fire from barrel staves and refuse wood built under the tank end was sufficient to heat the tar, sand and stone.
For mixing the materials a Ransome mixer was selected for the reason that heat could be supplied to the exterior of the drum by building a wood fire underneath. This fire was maintained to prevent the mixture from adhering to the mixing blades, and it proved quite effective, though occasionally they would have to be cleaned with a chisel bar, particularly when the aggregate was not sufficiently heated before being admitted to the mixer. A little "dead oil" applied to the discharge chute and to the shovels, wheelbarrows and other tools effectually prevented the concrete from adhering to them.
The method of depositing the concrete was practically the same as that used in laying cement sidewalks. Wood strips attached to stakes driven into the ground provided templates for gaging the thickness of the base and for leveling off the surface. The wood covering consisted of a layer of 2-in. planks, covered by matched hardwood flooring. In placing the planking, the base was covered with a ¼-in. layer of hot pitch, into which the planks were pressed immediately, the last plank laid being toe-nailed to the preceding plank just enough to keep the joint tight. After a few minutes the planks adhered so firmly to the base that they could be removed only with difficulty. The hardwood surface was put on in the usual manner. The prices of materials and wages for the work were as follows:
| Pitch, bulk, per lb. | $ 0.0075 |
| Gravel, per cu. yd. | 1.50 |
| Spruce sub-floor, per M. ft. B. M. | 15.00 |
| Hardwood surface, per M. ft. B. M. | 33.00 |
| Laborers, per 10-hour day. | 1.50 |
| Foreman, per 10-hour day. | 4.00 |
| Carpenters, per 10-hour day. | 2.00 |
At these prices and not including a small administration cost or the cost of tools and plant, the cost of the floor consisting of 4½ ins. of concrete, 2 ins. of spruce sub-flooring and ⅞-in. hardwood finish was as follows per square foot:
| Pitch | $0.04 |
| Gravel | 0.02 |
| Spruce, for sub-floor | 0.03 |
| Hardwood for surfacing | 0.035 |
| Labor, mixing | 0.03 |
| Labor, laying | 0.015 |
| Carpenter work | 0.025 |
| ——— | |
| Total per square foot | $0.195 |