We take the following abstract from the "Engineers," London:

The usual method of generating acetylene and calcium carbide is to treat the material with water. The gas may, however, be obtained if the carbide be brought into intimate contact with crystallized sodium carbonate, usually known as washing soda. The action in this case is to set free acetylene and to form water, caustic soda, lime and chalk. This reaction is made use of in the Atkins dry process for generating acetylene gas. The generator consists of a drum divided transversely into three chambers. The drum, as a whole, revolves on a horizontal axis. Into one ei:d chamber the carbide is introduced. The second or central chamber contains the soda crystals. The third chamber is filled with coke and serves for filtering the gas and holding back the dust.

This generator is revolved slowly about its axis. Motion in one direction causes a small part of the carbide to enter the second chamber, where it comes in contact with the soda. If the drum be turned in the opposite direction the carbide does not pass out of its chamber, but that portion which has entered the second chamber is mixed intimately with the soda crys-tals by means of a stirrer. Acetylene gas is then generated, passes through the filtering chamber, out through the hollow axis of the drum, then percolates through oil and is carried to the holder.

It is said that by revolving this generator for about twenty to twenty-five minutes, enough gas can be generated to last a residence for twenty-four hours. The generator is fitted with a safety-valve to protect it against excessive pressure, though the pressure generated at any time should be slight. The mixing chamber has a large cleaning door, through which the waste products are taken out. These are in the form of a dry powder and are removed without difficulty. Such a generator is six feet, six inches high and occupies a space twelve feet by six. This includes the holder also, which has a capacity of about 250 cubic feet, sufficient for 120 burners.