A considerable number of meltings in covered pots at 1400 deg C have been made of soda-lime batches in which amounts of moisture varying from 0.25 to 10 or even 15% were present. Some batches contained soda ash only as the source of alkali, others varying proportions of soda ash and saltcake. It was found that the ultimate composition of the glass was not materially affected by the amount of moisture added to the batch. In general, the presence of moisture had a beneficial effect on the rate of melting. In the case of wholly soda ash batches, the best amount appeared to be 1% and the maximum to be used should not exceed 2%. With saltcake present, 304% of moisture could be employed with advantage. Glasses made from moist batches apepar to become stiffer or more viscous in working, and when 5% of moisture ws added to soda ash batches, the glass obtained was stiff and lumpy. These differences in working were noted despite the fact that the chemical compositions of the glasses were closely alike. The question of residual water in glass was discussed and emphasis laid on the need of obtaining some definite measure of the working qualities of a glass.
