So that in these giant’s chambers we have real buildings, which imply high technical accomplishments and have preserved for us the usual form of the dwellings of those early times. In what manner the huge covering-stones were placed on the side-walls of the giant’s chambers is a problem still unsolved. Doubtless many hands were occupied on such structures; and the history of building teaches us that with the proper use of human strength--as, for instance, in ancient Egypt--great weights can be raised and placed in position with very simple tools--round pieces of wood as rollers, ropes, and handspikes. [Illustration: INTERIOR OF THE “MERCHANTS’ TABLE” This is the interior of the above dolmen. It will be seen that the earth has slowly risen a great height since it was erected, nearly covering the dolmen, thus indicating immense age. The principal supporting stone is covered with sculpture.] Some of these giant’s chambers, which were originally enclosed in mounds or barrows, are still preserved at the present day, and splendidly too. Very often the chamber was quite covered with earth outside; it then formed the centre of what was generally a circular barrow, often regular small hills ten to fifteen feet high and frequently over ninety feet in circumference. [Illustration: A PALACE UNDER A CLIFF: A REMARKABLE MONUMENT OF THE STONE AGE IN CLIFF PALACE CAÑON, COLORADO This is perhaps the most noteworthy of all the remains of the cliff dwellers, and indicates how considerable was the culture of those early people in America. ] The corpses were buried, not cremated. They were frequently in a crouching attitude, or that of a sleeper lying sideways with the legs drawn up to the body. The smaller graves often represent single interments; the larger or largest ones are mostly family tombs, in which numerous corpses were interred one after the other at different times. But this repeated use of the graves is found also with smaller ones, and even with stone cists. Only the last corpse then lies in a normal position, while, through the repeated opening of the grave and the later interments, the skeletons belonging to previously interred corpses appear more or less disturbed or intentionally put aside. The skulls of the corpses interred in the Neolithic graves are well formed, their size indicating a very considerable brain development. The corpses were no bigger than the present inhabitants of the same districts, and the form of the head corresponds partly with that of the present population of those countries. Nor do the skeletons otherwise differ from those of modern men.