140 Notices respecling New Books. 



by a mechanical process, iudependent of the stoker, a uniformitv 

 of temperature and regularly thin strata are preserved; and as it 

 is applied to the machine only once in t\\elve hours, at which 

 time also the retorts are cleaned out, there is a considerabls re- 

 duction of labour, and an increased certainty of operation. 



" A greater quantity of gas being obtained by tlie mode now 

 described, there will evidently be a considerable saving of expense 

 in the coal necessary to produce it, and in the quantity of fuel 

 employed. The sa\ang in the former will be proportioned to the 

 increase in the quantity of gas : and as that is more than double, 

 the sa\ing will amount, at least, to one half; and as the above- 

 mentioned quantity of gas can be produced at the heat usually 

 applied, and in a considerably shorter period than is now re- 

 quired, there will he a saving also in fuel of more than one half, 

 Besides, one chaldron of coal introduced into tlic retort upon the 

 proposed plan, produces two chaldrons of coke of excellent ([ua- 

 lity, which finds a ready sale at 255. per chaldron, when tlic coal 

 is at 50^. 



. '' Another advantage accruing from this niode of operation, is 

 a very material saving in the wear and tear of the apparatus. 

 Every one conversant with gas-works knows, tliat upon the plans 

 in general use, when 10,000 feet of gas are produced, the re- 

 torts must be renev.cd at least once in six months. Upon my 

 plan they maybe kejjt in good working order eighteen months. 



" Another very important advantage consists in avoiding tiie 

 nuisances hitherto inseparable from tiie preparation of coal gas. 

 The greatest inconveniences attending it have been the produc- 

 tion of tar and ammoniacal liquor, and the accumulation of the 

 lime-water used in purifying the gas. The two first are com- 

 pletely obviated by the proposed process of decomposing the 

 coals, neither tar nor ammoniacal liquor being produced in the 

 operation. The latter inconvenience is prevented Ijy the use of 

 lime and water in a semi-fluid state, which in being discharged 

 from the machine soon becomes consolidated, and may easily be 

 removed, and applied to any purposes for which lime is required. 



" To produce these advantages, I have constructed an appa- 

 ratus, a part of wliicli may be applied to works already established, 

 and of which the fo'lowing is a description. 



Descriplion of the Apparatus. 

 " The retorts are similar to those described in Accum's last 

 Treatise on Gas-Lights, under the head ' Rotative Retorts,' with 

 this difference, that the whole retort is heated to the required 

 temperature, and the space between the arms covered with iron 

 plates, the wide end of which projects upwards to the height to 

 which I propoic to allow tlic coke to liccuaiulatc. The whole 



forms 



