When the cribs are full, as the barrels are in Fig. 87, they wall form durable stone piers. Four such piers will support a house big enough for from two to four boys. In this case the foundation posts should be long enough to form the four corners of the house. To make the posts steady, nail two diagonal binders on the posts, from corner to corner, crossing them in the centre (Fig. 87). Let these diagonals be just above the water, and above these, and out of reach of waves, nail four More Binders, in the form of a square, as A, B, C, D, in Fig. 88 are arranged. These form the support for the floor, and four more at the top of the corner or foundation poles will make a support for the roof. The rest of the work is simple; it is only necessary to lay a floor, put on a roof, and to board up the sides to have as snug a cabin as boys need want in summer-time. By using more piers you can make a foundation of any size. [Illustration: FIG. 88.--A Finished Foundation.] When The Bottom of the Pond is hard sand, or stones, the basket-cribs may be built on shore in the same manner as described, but in this case it is neither necessary nor advisable to drive the stakes far into the earth. When finished the crib will hold together and may be removed from the land without dislocating the stakes, as the vines will hold them tightly in the structure. [Illustration: FIG. 89.--Barrel Cribs.] You cannot possibly force your corner posts into the soil through hard sand or stones, and you must, therefore, be content to rest their lower ends upon the bottom, in which case make a stand for them by spiking two short boards, in the form of a cross, on the lower end of the posts, then slip your cribs over the posts (Fig. 89). While two boys hold the post and crib in place the others can fill the crib with cobble-stones, which will steady the post until it is made entirely secure by diagonal braces and the four binders, A, B, C, D. No matter how uneven the ends of the posts may be at first, the top of the binders, A, B, C, D, must be exactly level. The water, when calm, is Always Level, and if you measure three feet from its surface, and mark the point on each post, you can make the binders exactly level by nailing them with their top edge exactly even with the three-foot mark on the corner posts. The posts may now be sawed off even with the binders (Fig. 88) and the floor laid. In a Large Building,