PLYMOUTH INSTITUTION. 233 



force, both of which it would and did supply in qualities of 

 which the limits were not yet ascertained nor calculated. 



The great objection to its use was the black dense smoke it 

 emitted ; the effects of which in the metropolis and in manu- 

 facturing towns were alluded to. The most effectual remedy for this 

 evil was, charring the coal, or converting it into coke; which was 

 at the same time the most powerful fuel known. Gas coke was 

 described as equal to most purposes of that substance; but the 

 Staffordshire coke was preferred, and the mode of its preparation 

 described. 



The great consumption of coke was in the iron furnaces ; but 

 it was available in malt houses, and wherever a clear, strong, 

 steady heat without smoke is required ; he thought it might be 

 used to advantage for culinary purposes, to a greater extent than 

 it was at present, where close stoves were employed. 



The remaining class of coal, culm, was carbon, nearly free . 

 from hydrogen, and containing a little oxygen and sulphur. It 

 gave a fierce heat, but was apt to split in the furnace, and fall 

 between the bars : hence its use, chiefly, in lime burning. It 

 would, however, answer many purposes of coke; giving an 

 equal heat, measure for measure, (but not taken by weight) and 

 more permanent. Its strong smell of sulphur, and its habit of 

 splitting being the chief objections. Its use might, however, be 

 advantageously increased in furnaces where there was a good 

 draught, which would allow the grate bars to be pretty close. 



The lecture was illustrated by many tables; of which we in- 

 sert a few of the most important : — 



ANALYSES. 



Turf,. ..A ^j)^"°a^^ \ 42 Gas 18 Charcoal 25 Ashes 15 

 Wood,.. Water 25 ^^Ta?er. 1^^ ^^^^^ ^^ ^t'']' 

 Lignite,. . ^ ^^uTq^^^' ] ^^ Charcoal 40 Ashes 8 

 Coal, Hydrogen 4 Oxygen 11 Carbon 81 Azote 4 



EFFECTIVE POWER OF DIFFERENT FUELS. 



"o Coal, would heat, . 60 



T3 TCoke, 66^ Pounds of water, from the freezing 



§ 1 Wood, 27 ^ to the boiling point, if all the 



p- J Charcoal, 75 I heat produced could be contrac- 



(V r Turf, 25 1 ted in the water. 



O Charred Turf, .... 60^ 



Lignite, rather superior to Turf. — Culm, rather inferior to Coke. 

 VOL. VI. — 1835. FF 



