Before we conclude this article, we think it right to give a few useful rules to those who may have the management of the gas light apparatus. These arc the substance of the rules drawn up by Mr Clegg for the use of the workmen.
1st, Before closing the retort, take common clay, dried, pulverised, and sifted, to which add as much water as will give it the consistence of treacle ; make both the surfaces where the lid fits the retort very clean, spread the luting thinly over the turned part, then secure the lid in its place by the wedge, Fig. C, Plate CCLX1V. If this is not strict ly attended to, the retort will lose the gas, and the smell will be very offensive, and injure the health of the operator.
2d, The bridge of bricks, b b, Fig. 2. which separates the fire place from the retort, must never exceed a bright red heat. If they are raised to a white heat, the gas will be in jured, and the retort be soon destroyed. This may be re gulated by a damper in the chimney, or by the register door to the ash pit. See Fig. 7.
3d, The gazometer should be examined at least once a week, which is done as follows : shut the stop-cock y, Fig. 7. and likewise the retort from the gazometer, no operation going on. Mark the suspended vessel at the surface of the water when it is nearly full of gas. If the mark sinks be
low the surface, there is some opening where gas es capes. To find out this place, walk slowly round the ves sel, and if the leak is not very small the gas may be smell ed. Apply a candle to the place, and the issuing gas will be inflamed. Mark the place, and blow it out. In the same way search the vessel all round. There, however, may be a small leak, and yet it will not inflame. About the sus pected part apply with a brush a little white lead paint. The place where the gas escapes will become yellow, and ultimately black, from the sulphur in the gas. The place being discovered, take a small piece of linen, clip it in a little melted pitch and bees wax, and apply it to the part while hot, and keep pressing it on till it is cold.
4th, Keep the water in the outer vessel of the gazome ter at its proper height, in order that the gas may have to rise through the same column of water.
5th, In the place where the lights are, appoint one person only to superintend their management. Be careful to shut the cocks when the lights are not wanted, and do not suffer them to be opened till they are to be lighted, and then hold a lighted paper over the aperture while the cock is turned. Do not use a candle for this purpose, lest it drop on the burner. (c. s.)