134 CEMENT CONSTRUCTION size that no reinforcement is necessary in the walls. On the upper edge of the walls, and around the interior, may be embedded strips for use when the glass frames are placed on top. Remove the forms in two or three days, and keep the walls damp for a couple of weeks.
The greenhouse foundation should be ten inches wide and sixteen inches deep. The mix ture should be one part Portland cement, three parts sand, and six parts crushed stone or gravel. On this, and at equal distance from each edge, a wall seven inches thick should be built. The mixture for this should be one part Portland cement, two and one-half parts sand, and five parts cinders. The wall should be carried up to the height desired, and a ridge-pole erected six inches wide and eight inches deep, with one part Portland cement, two and one-half parts sand, and five parts crushed stone or gravel not more than three-quarters of an inch in size. This pole should be reinforced with two steel bars half an inch in diameter. If the total width of the house is not over 16 feet, beams from the ridge-pole to the side walls inches by 5 inches, reinforced with a half-inch bar, will be strong enough. For the support of the ridge-pole, posts eight inches square should be placed at intervals of ten feet. The final or finishing dress for all the concrete should be a quarter-inch coat of cement mortar.
The first step, after the desired size is deter mined, is to make the pipe connections and pro vide for the feeding arrangements for the foun tain. A pipe frame or skeleton of pipe should be made, with the provisions for the spouts of water, all of which should tend a little inward to get a centralization of the streams. The pipe should be of size to assure a free flow, except the central or "trunk" pipe, which should be 2 inches. Four pipes, quartering the circle, should be joined to the center or vertical feed pipe.
The excavation for the ground basin should be made below the frost line, and provision made for draining the fountain by laying pipes that will carry the water off through an overflow vent. A foundation of crushed stone or gravel should be laid; and after this has been watered, the concrete can be laid, leaving a hole in the center for the pipe. A circle may be drawn with the pipe-hole as a center, and the work of laying the concrete should be carried on with this as the working point. The concrete, one part Port land cement, three of sand, and five of gravel, should be well tamped.
When the concrete has dried sufficiently to allow the work to proceed, attach the pipe sys tem, and place a circular form for the first sec tion of the central column, tapering up slightly and about 12 inches in diameter at the bottom. Fill with concrete, and tamp in layers of four inches. Place a saucer-shaped form far enough below the pipes of the middle basin so that they will be in the center when the concrete is filled in. This form should be about two inches more in diameter than the circle of pipe. Fill with concrete, trowel thoroughly, and proceed with the second section of the central column and top basin in the same manner.
The forms should not be removed for at least two weeks, at the end of which time they may be taken away, and the fountain given a finish ing coat of waterproofed mortar.
The forms for the basins will be best made of 2 by 6-inch lumber, each piece sawed out so as to give an approximate saucer shape when all are nailed together. Then the finish of the form may be done with a chisel. Ingenuity will find