In an aerated water machine, the carbonic acid may be generated in a small cylindrical gas vessel A (see illustration) made of stout sheet copper lined with sheet lead. The charge of bicarbonate of soda may be put in by unscrewing the cap B and dropping the soda down the wide tube C; the cap should then be screwed on again. The diluted sulphuric acid must be poured through the cap D, and remains in the cistern E until required, when the tap J? is opened and it is run into the solid charge in G. The carbonic acid passes by the pipe H, which is bent to prevent spurting of the contents into it. It passes into the charging vessel J, also of stout sheet copper, but plated with pure tin. The aerated water is run off by turning the valve on the counter. Sulphuric acid and bicarbonate of soda are used in preference to the seltzogene charges on account of being much cheaper. A gauge may be put on J, if desired, to show how much aerated water has been drawn off.

Aerated Water Machine.