This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
To stop natural syphon, close cock No. 1. To start acid by pressure, shut cock No. 1, and draw gas from generator. To stop flow of acid by pressure, open cock No. 1. Before bottling is stopped for the day, open cock No. 1, and work up the acid in the generator and draw it down by bottling to as low as you want it, say 40 lbs.; and if the charge is stirred before stopping work thoroughly, it will make no more gas during the night, and it is impossible with cock No. 1 open to get a drop of acid into the generator, through the feeder.
If no gas at hand to start the machinery, it can be done by pouring acid slowly and carefully through the bung in the generator; leave cocks No. 1 and 2 open until you have poured in sufficient acid to raise 5 lbs. gas, then screw on bung quickly and close cock No. 2.
The cock No. 3 is always closed when the machine is charged and working.
When gas is drawn from generator into fountains with cock No. 1 closed, acid will flow in and replace the gas drawn out.
The power to work the feeder is produced by gas. The power to stop the feeder is produced by gas.
When cock No. 1 is open (except when working a natural syphon), it is impossible to get acid over.
If the gauge is placed on pipe E between cock No. 2 and the bung in generator, it will indicate more correctly the pressure than if on cooler or acid head, and the gas cannot be shut off by cock No. 2. Or place it according to judgment of manufacturer.
It is also desirable to connect pipe F leading from G with generator, than to connect it with pipe E, as shown in cut, so there can be no possible way for water to get from cooler into acid head; this can be done by connecting pipe F with the bung shown in cut on generator, instead of connecting with pipe E as shown in cut.