Gold-solder
Take gold of the same quality as the article to be soldered, and add 1/12 of silver and 1/24 of copper. A larger proportion of silver and copper may be added for articles not so fine. See SOLDERS. Gong-metal is composed of copper 78 to 80, tin 20 to 22. After casting, the metal is subjected to a process of hammering and annealing. Owing to the brittleness of the mixture, great care and judgment is required to beat it into the flat basin-shaped gong, which, when struck with the mallet, puts the metal into such an extraordinary state of vibration as to produce the piercing sound emitted. Annealing is obtained by heating to a dull red, and suddenly immersing in water. When cold, the hammering can be continued until a point of brittleness is reached, when a repetition of the annealing process is made necessary, and so on until completed. See ALLOYS; BRASS.