BUILDINGS.
The structures which man erects are intended to subserve one of two purposes : they are either shelters from the weather or they are defences against his foes ; the one or the other character prevailing to such an extent as to decide on the form, material, and location adopted.
Primitive may suppose there was a period when the creature called man did, as the poets would have us believe, dwell in caves and hollow trees. But communities have never been found of whom this was literally true, nor does the analogy of nature require it. Man, like the beaver, the squirrel, and the birds, belongs to a home building species, and probably always builded. The savages who peopled Buenos Ayres when the great ice-sheet had scarcely disappeared from the surface of its vast plains, and who were coeval with the fossil horse, col lected the thick armor-plates of glyptodons, and with them constructed shelters against the storms (Florentino Amegbino). The naked Botocudos of the Brazilian forest and the " blackmen " of Australia know how to bend saplings together and thatch them with leaves as a protection against the tropical sun and showers (see pi 5, fig. 4; comp. pl.. 45, jig. 6).
It is instructive to note how strongly nations differ in this art. Some are persistent builders, utilizing whatever material they have at hand, while others seem unable to avail themselves of the most obvious hints of nature. This is seen within the limits of the same race. Thus, the ancient Peruvians, of different tongues but of similar characteristics, constructed edifices of wood and stone, of bricks, concrete, and thatch with equal facility as one or the other material was abundant ; while the tribes east of the Mississippi, several of them of signal intelligence, never in any instance rose to the level of laying stones to form a wall. In an cient India the Dravidian tribes offered examples of the same contrast of dispositions. In the Arctic zone the Eskimo with admirable ingenuity builds his dome-shaped winter-house of blocks of snow, and reserves his skin tent for summer ; but the Lapp and Samoied have for ages been exposed to a similar climate and never developed this skill.
A skeleton of poles covered with skins, leaves, or mats was in most climates the first artificial shelter, and long survived in the " osier huts " of the English peasantry. As they were of such perishable material, they left no traces. Nomadic tribes still cling to the tent of skin or woven stuff, which they can readily fold and carry to their next camping ground. Agricultural occupations demanded more permanent residences. They were at first usually of wood. Where this was scarce, clay was kneaded and baked in the sun to form adobes, or sun-dried bricks, which could be laid firmly in the wall by a mortar of the wet clay itself. All the so-called brick building in ancient America was of this character. Hardening the bricks by "kiln-drying" was unknown.
Stone Wails without walls were at first "dry walls," the separate pieces laid together as they would fit most securely. Such were the "Cyclopean " or Pelasgic walls of Greece, the constructors of which are lost in the night of time ; and such were the walls of those equally obscure and far more wonderful remains on Lake Titicaca in Peru. Nowhere else was this system carried to such perfection as in the last mentioned country. Many of the " Inca walls" remain as marvels to this day. The stones, often of gigantic size, are so accurately jointed and adapted one to the other, without the use of any cement, that not even a knife-blade can be inserted between them ; and this after the lapse of four or five centuries since they were laid in the wall (see pi. 52, figs. 2, 8).
Stone Wails zcith mingling of lime—at first obtained from burnt shells—with sand to form mortar led to a further development of building. It was an independent discovery in different localities. In America its northern geographical limit is marked by the " cliff-houses" of the callous of the Colorado. These birdnest-like dwellings, perched on the sides of lofty precipices, are of stones laid in a gray and exceed ingly tenacious mortar. In some specimens from ancient Egypt and Rome the stone or brick itself will give way before the cement in which it is laid.