CERAMICS
GROUND CERAMICS—LAYING OIL FOR: See Oil.
Notes For Potters, Glass-, And Brick-makers.
To arrest the unsightly defect of “crazing,” the following have been the most successful methods employed, in the order given:
I.—Flux made of 10 parts tincal; 4 parts oxide of zinc; 1 part soda.
II.—A calcination of 5 parts oxide of zinc; 1 part pearl ash.
III.—Addition of raw oxide of zinc, 6 pounds to each hundredweight of glaze.
To glazed brick and tile makers, whose chief difficulty appears to be the production of a slip to suit the contraction of their clay, and adhere strongly to either a clay or a burnt brick or tile, the following method may be recommended:
Mix together:
| Ball clay | 10 parts |
| Cornwall stone | 10 parts |
| China clay | 7 parts |
| Flint | 6 1/2 parts |