THE ART OF CASTING BRONZE IN JAPAN. 647 



the destruction of a temple by fire, when the bronze, brass, and gokl 

 vessels of the altar were melted together into a mass. The beautiful 

 color of the metal attracted the attention of some art founders, who, 

 after numerous unsuccessful attempts, at last succeeded in producing 

 an alloy resembling- it. . Gold is said to be an essential ingredient in its 

 composition, but I have not found any in the specimens I have exam- 

 ined. It is not in very common use. Vases and otlier objects cast of 

 it — generally with but little ornament in relief — are occasionally met 

 with, but the finest specimens are found among the guards and other 

 ornamental furniture of the sword, and all are chiefly notable as exam- 

 ples of chasing rather than of founding, or for the beautiful color and 

 texture of their surfaces. 



The method of preparing or melting bronze is, as is well l^nown to 

 all founders, secondary only to its correct comijosition, and as it has 

 such an important influence on the character of the castings, one or 

 two points relating to it, derived from my own experience, may be 

 briefly considered here. Cupola furnaces should never be used for any 

 bronze castings. If coke is employed as fuel in them the metal will be 

 contaminated with sulphurous anhydride (SO^), and the casting will 

 be vesicular. This may be avoided by using charcoal, but with either 

 fuel the bronze will be of uncertain composition. The Japanese method 

 is in this respect decidedly faulty. 



For castings of small or moderate size the bronze should be melted 

 in plumbago crucibles. For large castings requiring the contents of 

 several crucibles a vessel of sufficient capacity should be provided into 

 which the metal from all the crucibles should be i)oured, and then from 

 it into the mold. 



The bronze should not be stirred with iron rods, or it will be con- 

 taminated with iron, but with plumbago stirrers. This method should 

 be adopted whenever practicable, even for castings of considerable size, 

 and the fuel used should be charcoal or specially selected coke as free 

 as possible from sulphur. 



For colossal castings reverberatory furnaces must be used, and when 

 worked with care they give satisfactory results. A point apt to be 

 neglected in these furnaces is the proper mixing of the alloy — not a 

 diiflcult matter, but requiring more supervision than is often given to 

 jt — and everyone who has had to make many castings with them will 

 have occasionally found crusts of a white alloy attached to the sides of 

 the hearth, indicating that some of the castings did not contain their 

 full amount of tin. 



A second point of importance which is often overlooked is the liabil- 

 ity of the metal to absorb sulphurous anhydride (SO2) from the prod- 

 ucts of combustion of the fuel. This may be prevented by keeping a 

 sufficient supply of charcoal on the melting hearth while the copper is 

 being melted, and afterwards a thick layer on its surface, and at the 

 same time guarding against a large accumulation of ashes and clinker 

 in the fireplace. ■ ^ 



