"Yes," chimed in the Doctor, "and we may compare this Peruvian Tiahuanaco to the Egyptian Thebes and Karnak. What we find here is very much like what we found in those old cities of the East." "But I'm coming to a still closer comparison to Thebes and Baalbec," said Fred. "You remember the great stones of Baalbec, and how much we wondered at them?" Frank nodded assent. [Illustration: FRONT VIEW OF MONOLITHIC DOORWAY.] "Well, here in Peru," was the reply, "we find there was a doorway made of a single stone, which is still standing, though it has been broken by an earthquake, or by lightning--the natives say by the latter. Here are the figures of its measurement, as given by Mr. Squier: "Thirteen feet five inches long, seven feet two inches high above the ground, and eighteen inches thick. Through the centre is a doorway, four feet six inches high, and two feet nine inches wide. The upper part is carved with figures in low relief, much like the sculpture we saw in Egypt, and Mr. Squier says he does not believe there is a finer piece of cutting in the same kind of stone on this or any other continent. [Illustration: SYMBOLICAL SLAB.] "In another enclosure is a horizontal slab of stone about fourteen feet square, with a deep cutting in the centre, which is supposed to have something to do with the religious observance of the people who made it. The building that contained it was constructed of blocks of stone fourteen feet long, and of corresponding depth and thickness, and all the work was performed with great care." Frank asked what the Peruvians used for hewing the stone of which these buildings were made. "As far as we can learn," replied the Doctor, "they were unacquainted with iron or steel; they were familiar with bronze, and some implements of this metal have been found. They had no knowledge of gunpowder, or other explosives, and it is not at all probable that they had any other power than that of men. The blocks found at Tiahuanaco must have been brought a considerable distance; they are of red sandstone, slate-colored trachyte, and dark basalt, none of which are found in the vicinity. There are cliffs of red sandstone about fifteen miles away, while the other stones are not less than forty miles distant. The conclusion is inevitable that the huge blocks in the ruins were transported from the cliffs I have mentioned." "Egypt again," said Frank. "The stone for the Great Pyramids was carried across the Nile from the present site of Cairo, and the red granite blocks at Thebes, Sakhara, and other places were floated down on boats or rafts from the first cataract of the Nile." [Illustration: TERRACE WALLS AND SCATTERED BLOCKS OF STONE.]