UPPER HUTT EXPLOSION TO BE EDITOR.

Evening Post, Volume LXXXVII, Issue 77, 1 April 1914, Page 8

UPPER HUTT EXPLOSION TO BE EDITOR.

Sir,— -As considerable uncertainty has been expressed by statements in your paper as to the possible danger from the Use of acetylene, we would ask you to publish the following facts for the information of your readers. There required to be a 1 minimum of 4 per cent. of. acetylene in a room to allow an explosion to be caused with a flame. A room measuring 10 by 10 by 10, equalling 1000 cubic feet,, would require 40ft of acetylene to be accumulated in the room to produce an explosive mixture. A large burner passes one foot of gas per hour, and would, if left open, take forty hours to pass the necessary gas. During this time the mixture would be weakened by leaks of air into and from the rooni^ and an explosion from such a cause is impossible. A gas pipe, broken clean off, would allow the total supply from the generator to accumulate into the room, but as the stored quantity in the generator does not exceed a few feet, the available supply of gas will depend on the quantity of unused carbide in the generator. This quantity is limited, and the generation of gas from a fully-charged chamber would take about an hour to exhaust the chamber. In practice, it is hardly possible to have an explosive mixture in a room, even if a main gas pipe is broken clean off. If by any chance such a quantity of acetylene could be accumulated into a room as to produce an explosive mixture, the result of the explosion of this mixture by coining into contact with flame would be no more than that of a similar explosion of coal-gas, and the effects of the explosion would be the shattering of the window glass, if closed, or the force would be driven through the door, if open. In the case of the late disaster at the Hutt_. the generator only held seven, pounds of carbide,_ when fully charged, and this had been in use for lighting the premises during the evening. At the most, there could not have been available more than 20ft of gas, which, obviously, could not have caused any explosion there at all. Mishaps from the mis-use of any gas or light are possible, but acetylene lias proved itself to be as free, if not freer, Irom such risks than any other lighting agent, and the more_ this gas is known the^ more readily this fact is admitted. — We are, etc. For the Daylight Acetylene , ] Lighting System, F. J. SHELTON. For the New Zealand Acetylene Gas Lighting Co., Ltd., ! PHILIP CONGREVE. j