GAS-WORKS 623 



showing the slightest omission of light in a dark room, ignited a jet of gas almost 

 immediately. For opening and closing the gas-passage leading to the burner, and 

 lighting and extinguishing the gas as required, by simply altering the pressure in the 

 main, ho combines a bell-shaped compartment with the gas-pipe and the vessel con- 

 taining the electromotive liquid in such a way that when the gas is at its lowest 

 pressure the liquid seals the gas-pipe. By increasing the gas-pressure the passage 

 to the burner is opened, and by a still farther temporary augmentation of ^ the gas- 

 pressure, the galvanic circuit is completed, so that the issuing gas, impinging upon 

 the platinum wire between the poles of the battery, is ignited. In its most simple 

 form his apparatus constitutes a hand-igniter, to be used in lieu of matches, spills, or 

 tapers for lighting gas at any burner. It consists of a thin, hollow, glass vessel, 

 several inches high, closed at the bottom, and provided with a cover which screws 

 into a mounting attached to the neck of the vessel, so as to hermetically close it. The 

 cover has fixed to it, and carries beneath it, the galvanic pair, consisting of a perforated 

 tubular piece of zinc, and a cylindrical piece of graphite or carbon. Above the cover 

 are the electrodes, connected by a piece of platinum wire. The electrodes consist of 

 two brass wires, one of them screwed into the metal cover, which is in direct contact 

 with the zinc ; the other passes to the carbon through the cover, from which it is 

 insulated. The electromotive liquid used is the well-known mixture of bichromate of 

 potash with dilute sulphuric acid. In order to light gas with this simple apparatus, 

 it is only necessary to incline it sufficiently to bring the liquid into contact with the 

 zinc-and-carbon pair, and at the same time to hold the platinum wire in contact with 

 the jet of gas issuing from the burner. When the apparatus is placed in an upright 

 position, the zinc and carbon do not touch the liquid, consequently no galvanic action 

 takes place, and no material is consumed. 



' The street-lamp arrangement is designed to simultaneously light or extinguish a 

 number of lamps from a single station. But Professor Klinkerfues, considering that 

 galvanic batteries intended for the production of caloric would be of weak resistance, 

 and therefore incompatible with great lengths of conducting wires and long duration 

 of galvanic action, without frequent renovation of the liquid, decided to furnish each 

 lamp-post with its own galvanic apparatus, and to make the galvanic pair touch the 

 liquid only during the short time necessary for lighting up. In his apparatus for 

 this purpose the vessel containing the liquid is provided with an internal tube leading 

 to the burner, and having an enlargement at its lower part, as already mentioned. 

 This tube is attached at its upper end to the cover. The gas-pipe enters the vessel at 

 its lower part, and terminates within the tube. The carbon rests upon the enlarge- 

 ment of the tube leading to the burner ; and the zinc, in the form of a ring, which is 

 insulated from the tube, is attached to a screwed wire or rod, surrounded at its lower 

 end by insulating material, and passing up through a suitable insulator in the cover 

 to a connecting bar, upon which rests a nut, whereby the zinc is held and adjusted. 

 One of the electrodes is attached directly to the connecting bar, and the other is insu- 

 lated from the bar and attached to the cover. The upper end of the gas-pipe, situated 

 within the tube leading to the burner, is perforated, and a cap, adjustable by a 

 screw, which screws into the pipe, fits easily over it, the lower end of the cap 

 passing down below the level at which the liquid stands when the gas is at its lowest 

 pressure. An annular space is thus left between the cap and the gas-pipe, and the 

 interior of the latter communicates by the apertures at its upper end with the annular 

 space. 



The action of the apparatus is as follows : When the gas is at its lowest pressure, 

 and the surface of the liquid in the annular space between the gas-pipe and its cap is 

 at or about its highest level, the liquid seals the lower part of that annular space, 

 thereby preventing the passage of gas into the tube and thence to the burner. By 

 slightly increasing^ the pressure of gas, it will force the liquid down in the annular 

 space, thereby raising the level in the main vessel until the gas is permitted to pass 

 by the tube to the burner, and then, by a still further augmentation of the gas-pressure 

 for a few seconds, the liquid is temporarily forced up in the vessel into contact with the 

 zinc, thereby completing the galvanic circle, and igniting the gas issuing from the 

 burner as it comes in contact with the heated platinum wire. After this is effected, a 

 slight remission of the gas-pressure causes the level of the liquid in the vessel to fall 

 below the zinc, thereby breaking the galvanic circuit in order to avoid unnecessary 

 exposure, but without shutting off the supply of gas to the burner. The extinction of 

 the light is effected by reducing the pressure, so that the level of the liquid rises up 

 within the annular space between the pipe and its cap, and thereby shuts off the 

 communication, to the burner. The apparatus is accommodated to variations of 

 pressure at different altitudes, by adjusting the position of its cap, and the extent to 

 which it dips in the liquid by means of its screw. 



' The practicability of this apparatus was first publicly demonstrated by a three 



