GAS-METER 



605 



but a similar arrangement of retorts may bo adopted to that in general use in gas- 

 works, a is tho retort, sot in a suitable furnace for heating the same ; and b b aro 

 mouthpieces and lids, fitted to both ends of 

 the retort, c is the pipe for carrying off 

 the gaseous products generated in tho re- 

 tort ; and d is a pipe for introducing into 

 the retort the gas which is intended to mix 

 with the gaseous products of the substances 

 under distillation in the retort. As soon 

 as the retort is charged with coal or ether 

 carbonaceous matter, a cock e, in the pipe 

 d, is opened, which allows the gas to flow 

 into the retort ; and it then passes in the 

 direction of the arrows, and mingles with 

 the gas that is evolved from tho carbon- 

 aceous matters contained in the retort : 

 whereby a compound is formed, possessing 

 a much higher illuminating power than 

 could have been obtained had the combina- 

 tion taken place after instead of at the time 

 of the generation of the gas in the retort a. 

 The gas, which is brought to the retort by means of the pipe d, may be forced into 

 the retort, so as to overcome the internal pressure put on the retort by means of tho 

 hydraulic main ; or, instead thereof, an exhauster may be applied to draw off the gas 

 from the retort. Should tar. oil, resin (previously molted), or any liquid hydrocarbon 

 be employed for the generation of the gas, it is to be run into the retort in the way 

 generally adopted for making oil- or resin-gas. 



The sources from which the patentees propose to obtain inflammable gases, to be 

 applied as above indicated, are wood, sawdust in a damp or dry state, spent tanner's 

 bark, and other like substances capable of yielding an inflammable gas. These sub- 

 stances must be put into a red-hot retort, and distilled like coal. The resulting gases 

 may be either purified at once, or passed directly to the retort containing tho coal or 

 other carbonaceous materials. As a general rule, however, these gases are preferred 

 to be stored in gasholders for use ; as, in that case, a more uniform and constant 

 supply to the coal-retort may be relied on. 



Another source of inflammable gas is from coal of an inferior description, or from 

 peat. These substances having been distilled in a retort, the resulting gas can be then 

 employed as above indicated. It is also proposed to conduct carbonic oxide gas into 

 retorts containing carbonaceous matters under distillation. This gas the patentees 

 obtain from carbonic acid, by passing the latter gas (which may be obtained from any 

 convenient source) through a retort or furnace containing red- or white-hot coke. Or, 

 they utilise a portion of the gases generated in furnaces, by collecting these gases and 

 converting the carbonic acid they contain into carbonic oxide, by passing them through 

 a retort or furnace, as described for treating carbonic acid ; or the gases may be con- 

 ducted directly into retorts, wherein carburetted hydrogen is being generated, for tho 

 purpose of effecting the desired combination. See PEAT. 



From the foregoing description, it will be understood, that the object of this part of 

 the invention is to obtain gas of a uniform quality that is, possessing a definite 

 amount of illuminating power. Now, it is well known that if tho gas be too rich in 

 carbon it will burn with a dull flame, and give off a large amount of smoke ; and that, 

 if deficient in carbon, it will burn with a blue flame, and possess very little illumi- 

 nating power. It is therefore proposed to mix the rich and poor gases, obtained as 

 above described, in such proportions as will be needful to produce a highly-illuminating 

 quality of gas. As the proportions will depend entirely on the quality of the gases to 

 be combined, no rule can be laid down for the amount of the gas required to be passed 

 into the retorts, wherein the distillation is proceeding. The mode, however, in which 

 gas burns on issuing from tho retort will be a sufficient test for tho workmen in 

 attendance. 



GAS-METER. In order to measure the quantity of gas which passes through 

 a pipe for lighting a factory, theatre, &c., the gas-meter is employed, of whose con : 

 stniction a sufficiently precise idea may be formed from the consideration of Jiff. 1063, 

 . which shows the instrument in a section perpendicular to its axis. 



Within the cylindrical case a, there is a shorter cylinder b b, shut at both ends, and 

 moveable round an axis, which is divided into four compartments, that communicate 

 by the openings d, with the interval between this cylinder and the outer case. The 

 mode in which this cylinder turns round its axis is as follows : The end of the tube c, 

 which is- made fast to tho side of the case, and by which the gas enters, carries a 



