390 RELATIVE ATTRACTIONS OF 
where the sulphur is burning, must prevent the 
interior of the chambers from ever having so low 
a temperature as the external atmosphere in 
winter: to which I must reply, that towards the 
extremity of a range of several chambers there 
will not, I think, be found much difference be- 
tween the internal and the external temperature : 
but, even admitting that a considerable difference 
exists between the internal and the external tem- 
perature throughout the whole range, let the ar- 
gument be extended to summer temperature as 
well as to winter, and the result will give greater 
support to my views; for, then, for the same 
reason, it must be allowed that the internal tem- 
perature must be much higher than the external 
temperature, in the shade, (80° for instance, as 
before mentioned) ; and to this I may add that as 
the chambers are generally exposed to the direct 
heating influence of the solar rays, the internal 
temperature must, from that direct action of solar 
heat alone, be very much higher than the tempera- 
ture in the shade without. And, as the capacity 
of space for vapour increases in an increasing 
ratio as the temperature rises, the very much 
greater speed with which the aerial space is sup- 
plied with vapour in summer than in winter is 
undeniable. 
Bolton-le-Moors, May 28th, 1838. 
