Where a portable cylinder, instead of stationary carbonating apparatus, is employed, it is attached by its connections to the draught apparatus and then is ready for use, remaining in its position till empty, when a fresh one is substituted. They are in general constructed on the same principle as the stationary ones, without agitator. The European make have instead division plates securely adjusted in the interior to subdivide the gas bubbles and support the impregnation of the water in fountain. These portable cylinders should be made particularly strong, and in all cases tested to double working pressure. The connections and mountings are best of gun metal, heavy, and made for transporting and knocking about. The inside must be lined thoroughly with pure block tin, and every care should be used to prevent the chance of metallic impregnation. Fig. 320 is a sectional view of a European cylinder; the discs dd cause the water to become broken or agitated, while the gas is being forced in from the machine, the cylinder being rocked at the same time. When charged from the continuous machine, the gas and water are pumped together down the centre tube, which is represented by the spray at bottom; when charged from an intermittent (American) apparatus, the fountain is previously filled with water.

The fountain shown in Fig. 319 is made by the Iron Clad Manufacturing Co., New York.

These styles of fountain, illustrated by Figs. 321, 322 and 345 are usually used at the "Buvettes a Eau-Gazeuses". They are made of copper and are tin-lined.

Fig. 319.   American Portable Fountain

Fig. 319. - American Portable Fountain.

Fig. 320.   Sectional View of English Portable Fountain

Fig. 320. - Sectional View of English Portable Fountain.

Glass or porcelain-lined portable fountains would be the best; however, glass and porcelain linings are greatly liable to crack, and this being such a serious objection they are seldom made.

Fig. 321.   French Portable Fountain   I

Fig. 321. - French Portable Fountain - I.

Fig. 322.   French Portable Fountain   II

Fig. 322. - French Portable Fountain - II.

The portable fountains are like the stationary ones, made either of copper or iron (steel), and we refer in regard to this to Part III. Sweated or soldered and riveted fountains are both claimants for superiority, excellence of make, and safety. Riveted fountains, the heads and bottoms of which are secured by rivets, also the side seams, and all the joints sweated and soldered, are advantageous.