coarse outline design indicated the part to be removed. The labor was executed either by sawing partly through the stone and deftly breaking off the fragment, or by pecking it away with a flint-point. Lastly, the surface of the planes was rubbed with flat stones or polishers to remove the traces of the chippings. Other processes also appear to have been employed. The artist drew his figure in coarse tracings, and covered with ashes the lines he desired to bring out in relief. The whole surface was then heated with fire; the parts which were subjected to the direct action of the flames were decomposed, and left hollow places, while those that were protected by the ashes remained intact.
For finishing his work, the sculptor had nothing better than a flint-point or a copper chisel, the only tools in use, for iron was unknown. He was obliged, in order to execute those colossal figures and the bas-reliefs which now make such an impression of astonishment upon us, to cut with those imperfect tools in a very hard rock to a depth of three or four centimetres. The fact of the performance of a labor of such length is a certain indication of the infancy of the society in which it was done, where man had not yet learned to appreciate the value of time.
The region of the piedras pintadas (painted stones) in South America extends from Guiana to Patagonia. They are found in the wilds of Brazil and La Plata as well as in the more civilized districts of Peru and Chili, and they betray everywhere a remarkable analogy. In the solitudes of Pará and Piauhy, Brazil, are numerous intaglio-sculptures, executed by unknown peoples; they represent animals, birds, and men, in various attitudes. Some of the men are tattooed; others wear crowns of feathers; and the picture is finished off with arabesques and scrolls. At la Sierra da Onça are drawings in red ochre, isolated and in groups, without apparent order, and the rocks of the province of Ceara and those of Tejuco are covered with tracings not unlike those on the rocks of Scandinavia. Humboldt describes intaglios on the right bank of the Orinoco, representing the sun and moon, pumas, crocodiles, and serpents, ill-formed figures defined most frequently by a simple outline and declaring little advancement in art.
Nevertheless, since they are cut in the hardest kind of granite, it is
- Mr. Wiener saw the natives excavating an irrigation canal in the valley of Chicama de Sausal, through a rock which stood in the way. The workmen piled ashes along the line of the edges of the canal, covered them with dried manure and burned it. After eight days they succeeded in forming by this process a channel through a granite rock containing a vein of basalt 1·20 metre wide, 0·80 metre deep, and 2·30 metres long.
- There has been found near Quito a chisel that was used in working the large blocks of trachyte employed in paving the roads of the Incas' empire. It weighed 198 grammes. The surface was worn, the edge was nicked, and the head appeared to have been hammered upon, all indicating that it had been subjected to long use. An analysis of a piece of it by M. Damour gave ninety-five parts of copper, a little more than four parts of tin, and slight traces of iron, lead, and silver.