The process of charging portable fountains with carbonic acid gas differs in no material respect from the method of charging stationary fountains. The principal difference is in the agitation of the water. In stationary fountains this operation is accomplished by means of a block-tin covered metal agitator, while in portable fountains it is effected by rocking or agitating the fountain itself on an apparatus known as a fountain rocker.

However, if the cylinders are charged at any of the continuous machines, rocking is not required, as the agitation or mixing of the gas and water is done in the condenser of the carbonating machine as it is being pumped into the cylinder; but if the cylinders are charged from any of the American or intermittent apparatus, they are filled previously with about three parts of water, and then put into the rocker to agitate the water and gas together. The perforated plates in the European fountains are for supporting the impregnation of the water with carbonic acid gas.

The fountain should be vigorously shaken while the gas passes in; and when the water will absorb no more gas, and the pressure stands at a hundred and fifty to a hundred and eighty, close the cock on top of purifier, also cock of fountain, and disengage the fountain. A frame on which the fountain can rest will be found desirable for the shaking. The second fountain should then be attached with the same process. If the operator has fountains remaining uncharged when the charge in the generator is so far exhausted that a hundred and fifty pounds pressure cannot be raised, the remaining gas may be saved by partially charging them. Should the pressure become greater than the required working point it will be indicated by the safety-valve; but it is at all times advisable to keep the pressure within one hundred and eighty pounds.

Care must be taken to have portable fountains never filled over three-fourths full of water, as there must be room for the liquid to move while being impregnated.

The precaution of removing the atmospheric air when charging these fountains should also be taken.

Connections are used for attaching and detaching machines and fountains. Fig. 323 shows the connections used in attaching the cylinders to the charging machines; C is the clamp, and E the clamp joint; D shows the male and female nuts. B shows the regular style with clamp-joint connection.

The multiply-cock (Fig. 324) enables parties to dispense beverages in seasons of great press of business without the necessity of stopping to attach a freshly charged fountain every time one is exchanged. All couplings and connections must be carefully tin-lined.

There are various forms of rockers for small dispensers. The cast-iron frame shown in Fig. 192 will answer very well. Another style is represented by Fig. 325; it is easily operated by the upright rod which agitates the water most effectually. This rod can be taken out; the frame is all made of cast iron, with wood-bearings for the fountains; manufactured by the A. D. Puffer & Sons' Manufacturing Co., Boston, Mass.

For large manufacturers it is well to be able to agitate a number of fountains at a time, and for this purpose a fountain rocker, as snown in Fig. 327, is used. It can be worked either by band or steam power. The charging pipe of the generator is connected to the rocker at the projecting hose. The fountains with the liquid to be carbonated are laid on the rocker, and the elastic pipes are coupled to them as shown. The fountain stop cocks are then opened, and the gas from the generator is allowed to enter by opening and closing each valve on the rocker, in succession, two or three times, until the liquid ceases to absorb the gas. During this operation the fountains are agitated by turning the crank shown in the figure. It will be noticed that, on the rocker, there are two valves to each fountain. One is for controlling the supply of gas from the generator, and the other from a pump, which is sometimes used to economize the compressed gas in the generator, which would otherwise be wasted. This rocker is manufactured by the firm of John Matthews in New York.

Fig. 323.   Connections for Cylinders

Fig. 323. - Connections for Cylinders.

Another large fountain rocker, as manufactured by the A. D. Puffer & Sons' Manufacturing Co., is shown by the illustration (Fig. 327)

Another large fountain-rocker, as manufactured by the A. D. Puffer & Sons' Manufacturing Co., is shown by the illustration (Fig. 327).

When liquid carbonic acid cylinders are employed for charging portable fountains, the same process in general is followed, and we refer in regard to this to the explanations and illustrations given in Part III., on this subject.

Fig. 325.   Hand Fountain Rocker

Fig. 325. - Hand Fountain Rocker.

Fig. 326.   Fountain Rocker   I

Fig. 326. - Fountain Rocker - I.

In regard to water, its purity and temperature, used for filling portable fountains, the same observations and carefulness is necessary as applied to stationary fountains, as hereinbefore explained.

A more perfect union of the gas with the water is attained if the water is permitted to remain quiet for a few hours after being well charged and agitated in the portable fountains. The carelessness in purifying the carbonic acid gas and in charging portable fountains explains oftentimes the inferior quality of many draught beverages, but even carefully prepared and faultless waters lose, by prolonged storage in those metallic fountains, somewhat of their original freshness and taste, frequently also gas, and this is especially observable where but a small dispensing trade is carried on, and the water in fountain consequently remains very long, especially when the fountains are large. Portable fountains are made in various sizes, like the stationary ones. The proper size for the dispensing counter are those fountains which hold the quantity required for one day only. Large ones for a supply of more than two days should not be employed. If the trade is so small that even a six-gallon fountain cannot be dispensed in one, or at most in two days, the sale in bottles or syphons is preferable.

Fig. 327.   Fountain Rocker   II

Fig. 327. - Fountain Rocker - II.

An accessory to a portable fountain is a relief-valve (Fig. 328) in case it is overcharged.

This valve is designed for a fountain cock, with relief device attached. The manufacturers, the A. D. Puffer & Sons Mfg. Co., Boston, Mass., explain: "It is quite common to charge fountains with very cold water. In this condition the water absorbs the gas rapidly, and the quantity in proportion as the water is cold. If fountains charged in this way to a high degree, say 200 pounds, are transported during the heat of the day, the temperature may be raised from 40 degrees to 70 or 80.

The pressure will be increasing rapidly as the water becomes warm, and at 80 degrees instead of having a pressure of 200 pounds, as indicated when charging the fountain, the pressure has steadily advanced to near 400 pounds. The faucet is so gauged that, when the pressure exceeds the amount desired, it opens, and allows the water or gas to escape, whichever may be desired, and a safe equilibrium maintained". This is quite true, and when by carelessness such a charged portable fountain is exposed to the sun or by careless drivers transported around for a considerable time in hot weather, an extreme pressure is the consequence, which even might become dangerous. In such cases this relief valve might be of good service.

Fig. 328.   Relief Valve for Overcharged Fountains

Fig. 328. - Relief Valve for Overcharged Fountains.