"Cover the metal with varnish; let it dry, and then draw your pattern with a sharp point—say, a needle—simply removing the varnish and exposing just so much of the metal as you wish to show black lines. Put strips of wax around the metal, and then pour on it a mixture of one part of acid to three of water. Brush away the bubbles, as they gather, with a feather, or the lines will be very ragged. Then pour out the acid and water and wash away all the varnish with turpentine. Then you will find your drawing engraved on the shining surface."
As one proceeds in hammering brass, there will be an ever increasing demand for new tools, to fit into the corners and twists of the design, or to produce a given effect in the grounding. If bought, these will cost a considerable sum, but they can easily be
Fig. 36.
manufactured at home from square steel rod, or wire, sold at the tool shops for this purpose. Cut
