tribe of Indians, north of the semi-civilized nations of Mexico and Central America, which had the means of subsistence to enable them to supply for such purposes the unproductive labor necessary for the work; nor were they in such a social state as to compel the labor of the people to be thus applied. As regards the antiquity of these monuments, apart from such facts as a total absence of any reasonable traditions as to their origin among the Indians themselves, and the existence of the largest and most ancient forest trees on the embankments and in the ditches of the various works, there are other facts which enable us to arrive at approximate conclusions upon this point. None of these works occur on the lowest formed of the river terraces which mark the subsidence of the western streams; and as there is no good reason why their builders should have avoided erecting them on that terrace, while they raised them promiscuously upon all the others, it seems to follow that this terrace has been formed since these works were erected; a conclusion supported by the important fact that some of them have been in part destroyed by streams which have since receded for half a mile and upward, and which under no present possible rise, from rains or other natural cause, could reach the works again. Upon these premises, the time since the streams have flowed in their present courses may be divided into four periods, corresponding to the four terraces which mark the eras of their subsidence, of which period the last and longest (since the excavating power of the streams diminishes as the square of their depth increases) has elapsed since the race of the mounds flourished. Another fact bearing upon the question of the age of these works is the extremely decayed condition of the human remains found in the mounds. Considering that the earth around the skeletons is for the most part wonderfully compact and dry, and that the conditions for their preservation are exceedingly favorable, while they are in fact in the last stage of decomposition, we may form some approximate estimate of their remote antiquity. In the barrows of the ancient Britons, in a moist climate and under unfavorable conditions as regards preservation, entire and well preserved skeletons are often found possessing an undoubted antiquity of at least 1,800 years. From these and other facts and circumstances equally conclusive, we may deduce an age for most of the monuments of the Mississippi valley of not less than 2,000 years. By whom built, and whether their authors migrated to remote lands under the combined attractions of a more fertile soil and more genial climate, or whether they disappeared beneath the victorious arms of an alien race, or were swept out of existence oy some direful epidemic or universal famine, are questions probably beyond the power of human investigations to answer.—The principal remains of antiquity in Mexico are the ruins of temples and of structures dedicated to defensive purposes. Those of undoubtedly high antiquity are most massive in character, and display remarkable evidences of taste and skill. It would seem that during the aboriginal rule the bulk of the inhabitants dwelt in rude structures of thatch and cane, which after a few years of abandonment would decay and leave no trace of their existence, except perhaps in the fragments of broken pottery which might surround them. Whatever of architectural skill the people possessed was dedicated to the construction of their temples and the residences of their chiefs, which were often included the one within the other. These temples were in nearly all cases pyramidal in form, terraced and truncated, and ascended by flights of steps usually built on an inclined plane running up the centre of one of the sides, generally that opposed to the rising sun. These structures perhaps better deserved the name of altars, or the Scriptural name of "high places," than of temples; an edifice built on the level summit in reality constituting the naos, or temple proper.
Mexican Teocalli.
The great temple of Mexico, which is described by all the early writers as nearly identical in form and structure with all the temples of Anahuac, consisted of an immense square area, "surrounded by a wall of stone and lime eight feet thick, with battlements ornamented with many stone figures in the form of serpents." The extent of this enclosure, which occupied the centre of the ancient city, may be inferred from the assertion of Cortes that it might contain a town of 500 houses. It was paved with polished stones, so smooth, says Bernal Diaz, that "the horses of the Spaniards could not move over without slipping." The four walls of this enclosure corresponded with the cardinal points, and gateways opened midway upon each side, from which, according to Gomera, led off broad and elevated avenues or roads. In the centre of this grand area arose the great temple, an immense pyramidal structure of five stages, faced with stone, 300 feet square at the base and 120 feet high, truncated, with a level summit, upon which
