The substructures, Fig. 79, A, B, and C, taken from Keller’s “Lake Dwellings,” will give general ideas of the foundations of the dwellings in Switzerland and Upper Italy. At A is seen the earliest type, which reveals the section of the piles, upper flooring, water-line, and sloping bank of the lake. The piles were sometimes composed of split trees or stems, but more often of stems with the bark on, and were of various kinds of wood; they were sharpened at the end by stone hatchets, and in later times by bronze or iron axes, and were driven into the sand or mud at a short distance from the shore. The heads of the piles were brought to a level, and planks or whole trees were fastened on them as beams; sometimes they were fastened on by wooden pins, and sometimes were “notched” into the heads of the piles. Cross-beams were often forced in between the uprights under the platform to steady the structure, and outside there was often fastened a clothing of wattle-work to act as a fender from various accidents. If it were found difficult to drive the piles into the bed of the lake to any great depth, artificial raising of the bottom was resorted to, by bringing cargoes of stones in boats and dropping them between the piles, thereby securing a perfectly secure substructure (Fig. 79, B). These artificial risings are called “stein-bergs.” [Illustration: Fig. 79.—Section and Plans, Lake Dwelling Substructures from Keller.] A, General idea of arrangement of Piles; B, shows the Piles driven into the mud, with stones thrown between them; C, Section of Fascine Dwelling; D, Diagram of Floor Fascine Construction from Niederwyl; E, Section of Irish Crannoge in Ardakillin Lough; F, Construction of Wooden Form (Niederwyl); G, Section of Lake Dwelling Beds at Robenhausen. Another and later variety of substructure is known as “fascine-work” (Fig. 79, C). Probably this fascine construction was the safest when the water of the lake rose in height. It consisted of layers of small trees or stems laid lengthwise, built from the bottom of the lake; these sticks or trees were interwoven, and at intervals upright piles were driven in to keep them in position, and on the top of this structure, above high-water mark, the flooring platform was laid. [Illustration: Fig. 80.—An Ideal Lake Settlement or Town. (From Keller’s _Lake Dwellings_.)]