When the machine is working, the pump draws at the same time the gas from the gas-bolder, and the water or solution from the pan at the side, generally called the solution pan. The gas and water are forced up through the valves into the cylinder, the gas entering first, and the water last, and both being thoroughly mixed by the agitator. The variations of pressure in the cylinder are shown by the dial indicator, and the lever safety-valve is set to blow off at any required pressure.
The Bottling Machine.—The aerated water made in the cylinder of the mixing machine, is passed through the tin pipe to an apparatus called the bottling machine, which stands near. This machine has now reached such a degree of perfection that it is made to perform three distinct operations, viz. filling, syruping, and stoppering the bottles, which operations are carried on almost simultaneously ; the machine may be efficiently worked by any unskilled person. All these improvements have been effected within the last few years. As the soda water trade developed, the necessity for a bottling machine which could be easily worked made itself seriously felt. The old-fashioned method of bottling by hand and knee, directly from the nose of the machine, had many disadvantages, the principal being that it required much practice to get rid of the air in the bottle, and to retain the gas ; and also that much trouble and expense was occasioned by having to compress the end of the eork, and to St it to the mouth of the bottle before finally stoppering. The methods which have been used to force in the cork by machinery are various. Simple and compound levers, racks and pinions, screws, besides many other forms, have each their advocates. Machines having arrangements to expel the air in the bottle, and different sizes of nozzle cones to suit different corks, wero patented pore than fifty years ago ; and self-supplying and corking machines about twenty-five years ago. The treadle which works the cup in which the bottom of the bottle is put before forcing its mouth against the filling nozzle, has been worked in several different ways, such as by a foot lever, by a hand rack, and by a lever connected with a saddle upon which the bottler sits, and in other ways. Machines filling very large quantities and worked by steam power have lately come into use; these are made self-syruping and corking, a slight variation in the form being made for internally stoppered bottles.
Tho bottling machines now in use are of two kinds, viz. those made to fill the self-stoppering bottles, and those made to fill the ordinary bottles. Codd's filling machine is shown in Fig. 287.
The bottle is laid on the table in the two hollows, the indented side being always kept uppermost. The guard and excentric motion containing the cup are then brought down over the bottle by means of the handle, which is lowered. forcing the cup to rise and so bringing the bottle up to the rubber nipple : by keeping the hand firmly upon the handle, the bottle is kept tightly against it. At the same time, the handle of the supply valve is turned, and the bottle filled up to the required height, that is to about the shoulder, which can be seen by looking through the holes in the bottle guard. The hand is then removed from the supply valve and the guard quickly raised, the mouth being still kept pressed against the nipple, until it is sufficiently high to allow the ball in the neck of the bottle to roll into its collar. The bottle may now be released into the left hand by simply pressing the handle up, and the machine is left ready for a fresh bottle.
The foregoing method is that adopted for bottling plain aerated water. In bottling saccharine waters, a syrup pump attached to the machine is brought into operation. The construction of this pump is extremely simple, and its action very effective ; it constitutes one of the most recent improvements effected in this class of machines, as it dispenses with the separate operations of syruping. The pump, which is made of glass, is shown in the figure attached to the upper part of the machine. It is connected with a receptacle behind coutaining the syrup, and is worked by a treadle in the following manner : when the bottle is laid on the table, as described above, and held up to the nipple by the handle at the bottom of the guard, the syrup is injected into the bottle by pressing on the iron treadle at the foot of the machine ; this is to be done before letting in the aerated water. When the foot is taken off the treadle, the spring on the top of the pump causes the plunger again to rise, and so draws a fresh charge of syrup into the pump ; it is then ready again for discharging into the bottle, the last action being entirely self-acting. The syrup pan or jar should be fixed, by preference, on a level with the syrup pump, but it may be above or below, if inconvenient otherwise. The connection between jar and pump may be made with ordinary flexible tubing. When not in use, the cock at the back of the pump should be turned off.