Blowpipes are made by themselves out of brass wire hammered flat and then bent into a tube. The engraving and chasing of the objects made are done with the sharpened end of a file, or any other suitable sharp piece of steel. It will be seen from the foregoing that the Navajo silversmith is dependent to a very great extent on materials and tools obtained from the whites, and without these the practice of his art would be difficult. Schools for mechanical processes like dyeing, metal-working, etc., would accomplish much good among these people. They could readily be taught to use the lathe and other tools, and would become good metal-workers. [Illustration: KWAKIUTL CHIEF HOLDING HIS COPPER, NORTH-WEST COAST The value of a copper is expressed in white single blankets of American make at 50 cents each. It is rated according to the amount of property given away at the festival where the copper is sold, and each sale adds to its value proportionally. He who can break a copper and cast away the fragment is considered great. ] Prescott says of the Mexicans: “They were as well acquainted with the mineral as with the vegetable treasures of their kingdom. Silver, lead, and tin they drew from the mines of Tasco; copper from the mountains of Zacotollan. These were taken, not only from the crude masses on the surface, but from veins wrought in the solid rock, into which they opened extensive galleries.... Gold, found on the surface, or gleaned from the beds of rivers, was cast into bars, or, in the form of dust, made part of the regular tribute of the southern provinces of the empire.”[266] Their mining was doubtless carried on by the fire-and-water process used by the Northern people, while gold from the river beds was possibly obtained in much the same manner as I have been told the Amerinds of Peru get it. Selecting a river that was known to be rich in the metal, a series of stone “riffles” would be arranged in the best place at the very lowest stage of the water. Then when the freshets came and swept the gravel across these rude affairs the gold would remain lodged there and on the subsidence of the stream could be readily taken out. There was undoubtedly a vast quantity of gold in the possession of the Mexicans and Central Americans, but this fact does not signify that they conducted mining operations on a large or continuous scale, for the metal had been accumulating, in the shape of idols and ornaments, for centuries. There was little lost or worn away, as they did not use it as a general medium of exchange. Their plumes in their head-dresses were often set in gold; rings of gold were worn in their ears and on their arms, and the same metal was wrought into a great many forms of ornament.