STONE STRUCTURES. or less extensive ruins of stone structures, the work of aborigines during prehistoric times, occur in many districts through out the 'Western Hemisphere; they range from simple cairns of loose pebbles to imposing tem ples of wrought stone. The types are too numer ous for easy listing; but several examples throw light on the technic of the ancient artisans. Thus most of the pueblos and eliff-dwellers of the south western United States and northern Mexieo are of coarse rubble—i.e., of natural slabs laid with slight regard to the production of even surfaces. Some of the ancient walls are of slabs finished off on one or both edges by smooth jointage planes so selected and laid as to form surfaces hardly less regular than cut stone; while Hodge, in 1899, found in New Mexico certain stone rning in which the walls were evidently smoothed by rub bing or gribding after the structure was other wise complete—the earners in one ease being neatly squared and in another beautifully rounded to a radius of several inches. Yet even these fine structures showed that the primitive mason did not grasp the principle of breaking joints or that of the mo•tar-bond. In Central Mexico and Yucatan massive stones were laid in substantial walls; but even here, as shown by Holmes, the quarrying and dressing were effected wholly with stone tools and by painfully clumsy met boil 'a, virile none of the builders grasped the principle of the arch. Much the same may be
said of the remarkable stonework of Peru. The arehitectural features of American stone struc tures (so far as architecture was developed in the Western 'Hemisphere) are described else where; but it is worthy of special note that the many-storied pueblo grades into the cliff-house, and this again into the cavate lodge dug into the softer stratum of the cliff, and this in turn into the simple rock shelter, the open cavern used for temporary lodgment by primitive folk every where. It may be noted also that the early Americans used stone structures chiefly for habi tations and places of worship, and seldom, if ever, for fortresses. True, rude fortifications of loose rubble crown hilltops adjacent to villages in Wisconsin and northern iNlexico, as noted by Bandelier and described by Mc( be under the local designation trincheras, while similar forti fications have been observed in other districts; yet even these are places of ceremonial observ ance as well as of defense—and true fortifications of stone are conspicuously absent from the greater part of America.