In the opinion of some observers, the enigmatical ruins on the plain of Tiahuanaco, a few leagues from the shore of Lake Titicaca, in Peru, carry us far, very far, beyond any such modern date. “Even the memory of their builders,” says one of the more recent visitors to these marvellous relics, General Bartolomé Mitre, “even their memory was lost thousands of years before the discovery of America.”[[11]]
Such a statement is neither more nor less than a confession of ignorance. We have not discovered the period nor the people concerned in the ruins of Tiahuanaco. It must be remembered that they are not the remains of a populous city, but merely the foundations and beginnings of some vast religious edifice which was left incomplete, probably owing to the death of the projector or to unforeseen difficulties. If this is borne in mind, much of the obscurity about the origin, the purpose and the position of these structures will be removed. They do not justify a claim to an age of thousands of years before the Conquest; hundreds will suffice. Nor is it necessary to assent to the opinion advanced by General Mitre, and supported by some other archæologists, that the most ancient monuments in America are those of most perfect construction, and, therefore, that in this continent there has been, in civilization, not progress but failure, not advance but retrogression.
The uncertainty which rests over the age of the structures at Tiahuanaco is scarcely greater than that which still shrouds the origin of the mounds and earthworks of the Ohio and Upper Mississippi valleys. Yet I venture to say that the opinion is steadily gaining ground that these interesting memorials of vanished nations are not older than the mediæval period of European history. The condition of the arts which they reveal indicates a date that we must place among the more recent in American chronology. The simple fact that tobacco and maize were cultivated plants is evidence enough for this.[[12]]
There is, however, a class of monuments of much greater antiquity than any I have mentioned. These are the artificial shell-heaps which are found along the shores of both oceans and of many rivers in both North and South America. They correspond to the kitchen-middens of European archæology.
In several parts of the continent they have been examined by competent observers and the question of their date approximately ascertained. I need not say this differs widely, for these refuse heaps of ancient villages or stations were of course begun at wide intervals.
Long ago I called attention to the singular size and antiquity of those I found in Florida and along the Tennessee River;[[13]] and the later researches of Professor Jeffries Wyman would, in his opinion, measure the age of some of the former by tens of thousands of years.[[14]]
Further to the south, in Costa Rica, Dr. Earl Flint has examined the extensive artificial shell deposits which are found along the shores of that republic. They are many feet in height, covered by a dense forest of primeval appearance, and are undoubtedly of human origin.
In Brazil such shell-heaps are called sambaquis, and they are of frequent occurrence along the bays and inlets of the coast. Some of them are of extraordinary dimensions, rising occasionally to more than a hundred feet in height. The lower layers have been consolidated into a firm, stony breccia of shells and bones, while the surface stratum, from six to ten feet thick, is composed of sand and vegetable loam supporting a growth of the largest trees. Yet even the lowest layers of this breccia, or shell-conglomerate, yield tokens of human industry, as stone axes, flint arrow-heads, chisels, and fragments of very rude pottery, as well as human bones, sometimes split to extract the marrow. The shells are by no means all of modern type. Many are of species now wholly extinct, or extinct in the locality. This fact alone carries us back to an antiquity which probably should be counted by thousands of years before our era.
At that remote period not only did a fishing and hunting race dwell along the Brazilian coast, but this race was fairly advanced on the path to culture; it was acquainted with pottery, with compound implements, and with the polishing of stone. We further know that this race was not that which occupied the land when the whites discovered it; for the human skulls disinterred from the sambaquis are, craniologically, almost diametrically opposite those of the Botocudos and the Tupis. Yet if we can trust the researches of Dr. Lund in the caverns of Brazil, the oldest skulls in these deposits, found in immediate connection with the bones of extinct mammalia, belonged to the ancestors of these tribes. Markedly dolichocephalic, they present an entire contrast to the brachycephalic type from the sambaquis.[[15]]
This class of monuments, therefore, supply us data which prove man’s existence in America in what some call the “diluvial,” others the “quaternary,” and others again the “pleistocene” epoch—that characterized by the presence of some extinct species.