The continuous apparatus of the German plan are represented and described next.

The generator E, vertical, of cylindrical form, is either made of thick hard-rolled lead or of copper, iron, and thickly lead-lined. The inlet r is for passing in the carbonate and water. Generally a small cock is adjusted on top of the screw cap for the escape of atmospheric air. f is the agitator, and near the bottom is the outlet for the residue. Tube c leads the eliminated gas over to purifier W. The acid chamber S, made in the same way and of the same material or of strong glass, as the pressure of the continuous apparatus is considerably less than on the intermittent apparatus. It is connected with the generator by pipe d, and the pipe c for equalizing the pressure. The pipes are fitted and connected with perforated rubber corks. At cock x the flow of acid is regulated. On the outside of the acid chamber is pasted a scale which indicates the quantity of acid spent.

The purifier W at the side of the generator is of wood, and generally only attached to larger sets of apparatus, and especially intended for removing particles of carbonate and sulphuric acid, which the evolving carbonic acid might carry over. The other purifier W on support is of strong glass, a so-called "Woulff bottle". With some apparatus all the purifiers are of strong metal, especially on intermittent apparatus, where they have to stand a high pressure.

The glass purifier W in Fig. 114 is connected with first purifier by tube n and by tube h with the gasometer. The tubes are generally of tin and tightly fitted in the purifiers with rubber, or, better, paraffined corks, through which the tubes lead. Near the bottom is a cock for the outlet of water.

The gasometer R is made similar to those already described and of the same material. The height of the bell and the depth of the tub must correspond. In order to remove the atmospheric air from the bell, push the bell entirely down to bottom of the tub, fill it at the opening y quite full with water to overflowing, and close it then. Other gasometers have a discharge cock for the escape of atmospheric air at the top. Through pipe h the gas enters and pipe o leads it to the pump. These pipes are of tin. As will be readily seen, the pipe h, through which the gas enters, terminates above the surface of the water, thus filling the bell directly. In the gasometer of English and French make, and also in other gasometers of German make, this gas pipe terminates under the surface of the water, thus being washed by the water in gasometer tub before it reaches the bell. This arrangement is of course optional. If the gas is purified thoroughly before it enters the gasometer, it may be led directly under the bell. Large establishments keep two gasometers.

Fig. 114.   Sectional View oF German Continuous Apparatus

Fig. 114. - Sectional View of German Continuous Apparatus.

The pump is in its essential parts of the same construction and draws water from the reservoir N and gas from the generator at the same time, like the last described of the French apparatus. For the regulating of the supply of water and carbonic acid gas there are separate cocks, a for water and b for gas, and the desired supply of each has to be regulated with them. The condenser or mixer M is of cylindrical form, horizontal, made of copper, tin-lined inside. The agitator is of brass, tin-lined, with several wings. Both the agitator and pump are set in motion by the fly-wheel Sch and the cock wheel H. Hand or steam power adapted. The condenser consists of two parts, bolted together at D and tightened with rubber or leather; the whole is fastened to a wooden or iron support A. An inlet for liquid, salts, etc., for mineral waters is at v. Here is generally a little cock attached through which the atmospheric air escapes. At m is the pressure-gauge attached also at some other part, generally a safety valve. It has to prevent an excess of pressure. The cylindrical body R is connected with the interior of the condenser, and securely fastened to it. C E is a metal plate covering tube R, with a rubber sheet between them to insure tightness. Lever B D A, with the weight G, presses upon the plate C E. When the pressure in condenser rises higher than the weight which the valve exerts, then the plate C E will be raised and the superfluous gas blows off. The little mixer t on top of the cylinder, made of brass, tin-lined inside, by cock u with the cylinder communicating, receives such solutions as may be added while operating, and after the atmospheric air has been blown off, especially salt solutions. An absolutely necessary part of the apparatus it does not represent, as the salt solutions may either be added to water in cylinder or in some instances mixed with it in an extra slate tank, and therefrom drawn by the pump; however, it is useful where mineral waters with iron, etc., are to be made and air has to be thoroughly ex-cluded, or the solutions have to be added after the liquid is already charged with gas. In this case it prevents loss of gas and access of air. Tube I equalizes the pressure in the little mixer and the cylinder, when the contents flow down. Another and differently constructed mixer for the salt solution is represented here in this cut (Fig. 116). It is very similarly constructed to the acid chamber on American apparatus and stationary, or occasionally adjusted on top of the cylinder as seen in Fig. 114. The flow of the solution is regulated by a plunger valve, and the whole attachment is put in operation where mineral waters are to be made, to which the salt solution should be added after the exclusion of atmospheric air. It is a simple contrivance, enabling an operator to add necessary components under high pressure when the condition for their solubility is most favorable; it saves the trouble of reopening the cylinder and consequently loss of gas, and prevents the access of air.