638 



THE ART OF CASTING BRONZE IN JAPAN. 



From an early hour iu the morning and while the melting was pro- 

 ceeding the foundry stafit' was engaged in preparing the molds for the 

 recei)tiou of the metal by heating them to redness. This was eifected 

 in tlie following manner: The mold (fig. 7) was placed on five or six 

 bricks, H H, to raise it above the earthen fioor of the melting room. 

 Its ingates, COCO and D D D D, were closed with stoppers of 

 clay and the conical tubes, F F, were fitted over its air outlets, E E, 

 to prevent any fuel from falling into them. A wall of fire-clay slabs, 

 G G, was now built up around it, the slabs being kei^t iu position by 

 hoops and bands of iron and an exteriud luting of clay, a space about 

 3 inches wide at its narrowest part being left between the inside of 

 the wall and the outside of the mold. A charcoal fire was then made 



on the floor below the mold, 

 and the space between the 

 wall and the mold was com- 

 pletely filled with burning 

 charcoal, which was mixed 

 with fragments of bricks 

 and crucibles to prevent the 

 heat from becoming too in- 

 tense. The interior of the 

 core was also partly filled 

 with the same mixture, and 

 two clay tubes were fitted 

 above it to serve the pur- 

 pose of chimneys. The tem- 

 perature of the interior was 

 regulated by i)artially or 

 entirely closing the upper 

 openings of these tubes 

 with tiles. The mold was 

 kept at a red heat for more 

 than two hours, by which 

 time the metal was nearly ready. The wall of clay slabs and the 

 draft tubes were now rapidly taken down and the fire was raked 

 away. The bricks 11 H, supporting the mold, were carefully removed, 

 and the holes through which the wax had run out stopped up with fire 

 clay. During their removal the floor below was sprinkled with water 

 and softened by shoveling, and on this the mold was allowed to rest. 

 Large stones were now piled around its base to steady it and the stop- 

 pers were removed from the ingates. The ingates, of which there 

 were seven — four about the middle of the mold and three at the top — 

 were fashioned in the form of small cups of fire clay about 2 inches in 

 diameter, each having three apertures, half inch in diameter, opening 

 into the channel leading into the mold. 



The mold was now ready for receiving the metal. On looking into it 



Vig. 7. 

 MOLD WITH OPEN CORE. SHOWING THE MODE OF HEATING IT. 



A, A, outer wall of the mold : B. 15, inner wall of the mold 

 or core; C, C, lower ingates; D, D, upper ingates; E, E, vents 

 oroutletsfor tbeair and gases; F, E, fire clay tubes ; G, G, 

 fire-clay slabs ; H, H, firebricks ; I, I, ignited cbarcoal. 



