Stránka:roll 1931.djvu/124

108 Woodcraft Birch Bark Roll Drop the chunk of silver into one part of sulphuric acid to fifteen parts of water so as to cover it, using a glass jar. Rinse well. Exceeding care must be used in the handling of sulphuric acid. Do not heat the solution. When clear and cool, run through a jeweler’s rolling mill, adjusting to the right gauge, and the silver is ready for use. The Navaho Indian pours his silver into moulds which he makes in stone. If he wishes to make a round button, with a home-made chisel, he chips out a round hollow place in a piece of sandstone, about a third of the desired size. He oils this with suet. Into this mould, he pours the melted silver, re- peating for as many buttons as he wishes to make. He then hammers each individual moulded bit of silver into the de- sired size and shape, and puts on the design. As to the anvil and crucibles among the Navahos, Dr. Mat- thews says: “For an anvil they usually use any suitable piece of iron they may happen to pick up, as for instance an old wedge or a large bolt, such as the king-bolt of a wagon. A wedge or other large fragment of iron may be stuck in the ground to steady it. A bolt is maintained in position by being driven into a log. Hard stones are still sometimes used for anvils; and perhaps they were, at one time, the only anvils they possessed.” In the making of all jewelry, the first step is to decide upon the design and to make a careful drawing, complete in every detail, of the article to be made. Bracelets Take a piece of 20-gauge silver, 6 inches long, and from 14 to 1% inches wide according as desired for the finished bracelet. (a) Punched Bracelets If a punched design is to be used, place the silver on the smooth side of a flat iron; or an anvil such as the Navahos use, and, with a small ball-peen hammer, begin at one end of the silver, and hammer with the round end until the whole surface has a hammered effect. Care must be used, because this is the upper side of the bracelet. Turn the bracelet over, and sketch accurately on the under