Steam ILngme* 3 
V. 133. 275. 21 V. 254. 23 V. 123. 335. 26 V. 
316. 
As there is no general index to these works, I appre- 
hend it will be useful to note the places where information 
on this subject can be found in them. 
The common histories of the steam engine, include a 
description of Savary’s, Newcomen’s and Cawley’s, and 
Watt’s. I shall add, some account of the improvements 
of Hornblower, Cartwright, and Woolfe. Also, Oliver 
Evans’s account of his steam engine. I do not know 
that I can get all the plates read}' for the present number, 
but I shall insert herein the methods of consuming smoke, 
because those plates are likely to be completed in time. 
On the means ^consuming the smoke, arising from 
large furnaces^ particularly from steam engines. 
I would premise, that smoke, is a mixture of aqueous 
vapour — charcoal — and carburetted hydrogen, distilled 
olF by means of heat from fuel. 
When a candle or a lamp burns in the common me- 
thod, they smoke. That is, the fuel instead of being burnt 
or consumed, is in part distilled away by the heat ; for as 
there can be no combustion but by means of the oxygen 
of the atmospheric air, and as the outside only of the wick 
is in contact with the air, the fuel with which the outside 
is impregnated, only can be burnt : the oil or tallow of the 
inside, is distilled away and forms the smoke. Part of 
this is caught and inflamed as it escapes into the air ; 
hence the flame of a candle extends beyond the point of 
the wick; but the whole of it is not burnt. What is not 
burnt is smoke. 
To remedy this M. D’Argand, the inventor of the pa- 
tent lamp, has contrived (by making the wick thiny and 
circular y and by admitting a current of air to both sides 
of the wick) to consume the whole of the fuel by supply- 
ing every part of it with atmospheric air in a strong cur- 
