METAL INDUSTRY. 435 



observed by Lehmann and Wagener in Kioto. ^ It is a peculiar 

 decarburising process, by which the surface of the kettle or pot 

 receives a structure like to that of soft iron or steel, and can then 

 be treated in the same way as in the Zogan-work on forged iron. 



The process of decarburisation of the surface is called Yakeru (to 

 burn), and is performed with primitive apparatus. Old damaged 

 rice kettles out of which the bottom has been knocked serve as 

 ovens. These are plastered over on the inside with a fire clay 

 (Oka-saki-tsuchi and sand mixed in equal parts), so that a cylin- 

 drical space of the size of the hole in the bottom, remains open. 

 The Kama or kettle thus prepared, is turned over upon a thick 

 plate or slab, three or four centimeters thick, made out of the same 

 fire-proof material, which serves as a grate, and is perforated like 

 a sieve for this purpose. In order to give this plate greater firm- 

 ness, it is bound around with an iron band. The holes have a 

 width of about 1*5 centimeters. In order to give the air free play, 

 several stones are laid under the edge of the slab. Then the 

 Tetsu-bin to be burned, whose outside has been carefully cleaned 

 beforehand from dust and sand, is placed in the Kama, directly 

 on the grate. 



The difference in size between the Kama and Tetsu-bin must 

 be such that a space of at least five centimeters remains open 

 around the latter. This open space is then filled with the best 

 charcoal in pieces the size of a nut, till the Kama is filled to the 

 rim, when the coal is kindled. 



In order to increase the draught, two or three Kamas filled in 

 the same way are set one over the other, forming a kind of 

 chimney. When the coals have ceased glowing, others are put 

 in, and when the second instalment is burned out, the Tetsu-bin 

 are taken out and turned upside down (with the opening under- 

 neath), set again in the Kama and burned twice in this position. 

 Under favourable circumstances, the surface is now sufficiently 

 soft and tough, as is ascertained with a file. It is often the case 

 that the furnace must be heated ten times. After the cooling the 

 decorations are then carved as in forged iron, without danger of 

 breaking the edges, or recoil of the burin. 



Until some twenty years ago, the decoration with such inlaid work 

 was limited to places on iron kettles. At that time sevtral skilful 

 workmen, formerly armourers of Kioto, especially Komai and 

 lyenori, turned their attention to the work, and have developed 

 since then this branch of art industry in an astonishing manner, 

 decorating large vases, smoking utensils, plates, dishes, and other 

 articles of cast-iron with remarkable artistic skill, hitherto unknown 

 The heliotype of plate XVII. represents a cast-iron vase of Komai 

 in Kioto, adorned with such Zogan work. 



In the summer of 1875 I obtained from a dealer in Kioto the 



^ I am indebted to the kind communications of these gentlemen (Engineer 

 Lehmann and Dr. Wagener, both now in Tokio) for the items given here. 



