part XVI

.—Copper 44 parts Zinc 49 parts Tin 3.20 parts Lead 1.20 parts

Formulas XIII and XVI are fairly fusible.

White Hard Solders.—

XVII.—Brass 20 parts Zinc 1 part Tin 4 parts

XVIII.—Copper 58 parts Zinc 17 parts Tin 15 parts

XIX.—Brass 11 parts Zinc 1 part Tin 2 parts {659}

XX.—Brass 6 parts Zinc 4 parts Tin 10 parts

XXI.—Copper 57.44 parts Zinc 27.98 parts Tin 14.58 parts

For Brass Tubes.—I.—Copper, 100 parts; lead, 25 parts.

II.—A very strong solder for soldering brass tubes to be drawn, etc., is composed of 18 parts brass, 4 parts zinc, and 1 part fine silver.

For Fastening Brass to Tin.—To 20 parts of fine, reduced copper, add sufficient sulphuric acid to make a stiff paste. To this add 70 parts of metallic mercury, and work in, at the same time applying heat until the mass assumes a wax-like consistency. Warm or heat the plates to be united, to about the same temperature, apply the mixture, hot, to each, then press together, and let cool.

«COPPER SOLDERS.»

The copper solders which are used for soldering copper as well as bronze are mixtures of copper and lead. By increasing the quantity of lead the fusibility is increased, but the mixture departs from the color and toughness of copper. The most commonly employed copper solder is the following:

I.—Copper 5 parts Lead 1