JAPAN
our. Their blue tints are developed under the action of the furnace.
The decoration in blue having been completed, the next process is to apply the glazing material. This consists of the Uwa-gusuri-tsuchi, reduced to an impalpable powder, with which, to increase its fusibility, lixiviated vegetable ashes (obtained from the bark of the Distylicum racemosum) are mixed in proportions varying according to the recipes of different potters. In former days no pains were spared in the preparation of this glazing matter. Weeks were sometimes spent in treating it, and in special cases such particles of the pulverised mineral as had passed through a three-ply strainer of fine cotton-cloth were alone employed.[1]
The porcelain is now ready for the final stoving. The ovens where this operation is performed are generally placed on the slope of a hill, in rows of from four to twenty. They are built in a very simple and economical manner. The sill is first prepared, and around it side-walls are raised to a height of about three feet. An arched roof of rude timber is then superposed, and on it is laid a mixture of fire-proof clay, cement, and tiles, worked into a plastic condition. This mixture is pressed and pounded with heavy mallets, until it acquires sufficient consistency to stand without the roof-frame. The interior is afterwards beaten with small mallets to harden and smooth it. The oven is then complete. Should repairs be required, they are effected by breaking out the damaged part, applying a frame inside, and filling the space with fire-proof tiles. As these repairs are repeated, the oven gradually comes to consist entirely of fire-proof tiles. It lasts about fifteen years, and even when of the largest dimensions costs only about fifty dollars. It will be understood that the oven used for the final firing is here described. That used for the unglazed porcelain is of similar construction, but much smaller. Each manufacturer has his own Su-yaki-gama, but the ovens for the last baking belong to the community and are hired to the various factories as required.
It is worthy of note that, despite the somewhat primitive- ↑ See Appendix, note 3.
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