Of course one length of pipe is not sufficient to go to any great distance, and a joint has frequently to be made, the solder used for this purpose being so easily melted and so readily combining with the pipe itself, which is of almost the same material, that the flame from prepared _tow_ blown to an intense heat by the _blow pipe_ is sufficient for the purpose. The rasp is used for filing the surface at the ends of the pipes where they are to be joined, and the _waxed rushes_ to try the joints in order to see that there is no escape of gas through some small hole. When the pipes are all laid and brought to their proper positions the fittings are fixed. Those which descend from the centres of ceilings are generally called chandeliers, and consist of a tube of metal fastened to the gas pipe, the end of which coming through the ceiling is furnished with an iron screw to fit the end of the tube. This tube is placed within a larger tube, from the bottom of which a still smaller one passes within the first. The gas therefore descends the tube from the ceiling, and enters the smallest tube, which communicates with the _burners_ that spring from the largest. The larger tube is intended to receive water, in which the end of the first tube rests, so that the gas is prevented from escaping, while by a nice adjustment of weights running over pulleys attached to the larger, the burners can be raised or lowered, as one tube slides within the other (_see large cut_). The _taps_ are placed at the burners to turn on or turn off the gas as it is required, and in order to fix and screw these, as well as to fasten joints in the fittings by means of _screw nuts_, the _pliers_ and the _wrench_ are used. [Illustration: Wrench. Tow. Tap. Rimmer. Clamps. Pliers. Drill Stock.] The _clamps_ are a sort of vice with grooved holes, for holding the taps and metal joints firmly while they are filed or otherwise prepared; the _drill stock_ is used for boring small pipes in order to make a branch to some other direction, and the _drill brace_ is intended for boring the main pipes, under which the large hooks are placed while a stock and bit attached to the upper screw makes the hole; the ordinary _braces_ are fitted to a _ratchet_ or cog wheel at one end, and are also used for making incisions by being worked backwards and forwards. [Illustration: Drill Brace. Braces. Stocks and Dies.]