BaILEy. | Artificial Mineral Waters. | 121 
wooden cylinder, passed into a gasometer or storage tank, then 
by means of a force-pump into a strong cylinder containing 
water and provided with an agitator. By this plan, after one 
‘‘batch’’ of gas was used the apparatus had to be cleaned out. 
The Continuous System.—In this ‘‘direct-action’’ process, as 
it is called, the gas is generated in a leaden vessel, just enough 
acid being brought in contact with the carbonate, usually mixed 
with water, to generate the gas. Then the gas is washed 
through water and allowed to expand in a ‘‘gasometer.’’ The 
‘‘soda-water machine’’ proper consists of a force-pump, which 
pumps, at the same time, water and gas into a strong cylinder, 
provided with an agitator to assist in the solution of the gas 
in the water. 
The Intermitrent System.— By this plan the gas is dissolved in 
water by the pressure produced in the generator from the chem- 
ical action of the acid on the carbonate, without the aid of a 
pump or gasometer. Of course, the greater the pressure the 
more gas the water will dissolve. In order to make the appa- 
ratus continuous, it is only necessary to have several generators, 
two at least, so that the material in one apparatus may be re- 
newed while the other is in use. There are often pumps at- 
tached to the apparatus as used in the United States, for filling 
the cylinders with water. The generators may be so arranged 
as to be horizontal and acid-feeding, or vertical and carbenate- 
feeding. 
The Liquid Carbonic-acid System.—This is the most recent, and 
bids fair to supplant all the other systems in localities easily 
reached by transportion. The liquefied gas, made by one of the 
processes mentioned below, is pumped into strong wrought-iron 
cylinders about four feet long by five inches in diameter. These 
cylinders are tested to stand four times the pressure that they 
ordinarily bear, and hold about twenty pounds of the liquified 
gas. This represents about 1100 gallons of gas at ordinary at- 
mospheric pressure, and will charge from 200 to 300 gallons of 
water, according to the pressure desired. As this gas can be 
purchased at twelve cents or less per pound, it it is evident that, 
