142 Count Rumford’s Enquiry concerning the Nature of Heat , 
more than 1175 parts; and the remainder of that which was 
actually disposed of in the experiment, = 10000— 1175 = 8825, 
(= a —x,) must have passed off through the bottom of the in- 
strument. 
Hence it appears, that the quantity of heat which actually 
passed off through the bottom of the conical vessel which was 
placed over ice, in 33^ minutes, was to that which passed off in 
39^ minutes, through the bottom of the other vessel, as 8825 
to 8404; and consequently, that the velocity with which the 
heat passed through the bottom of the vessel which was exposed 
to the frigorific rays from the surface of the cold platter, was to 
the velocity with which it passed through the bottom of the 
other vessel, in the compound ratio of 8825 to 8404, and of 39^ 
t° 33i; or as 10000 to 8025, which is as 5 to 4, very nearly. 
From these experiments and computations it appears, that 
the cooling of the hot body which was placed over the ice-cold 
platter, was sensibly, and very considerably, accelerated by the 
vicinity of that cold body ; may we not venture to say, — by the 
frigorific rays which proceeded from it ? 
I made several other experiments, similar to those just de- 
scribed, and with similar results ; but I shall not take up the 
time of the Society, by giving a detailed account of them. I 
may perhaps, at a future time, find occasion to mention some 
of them more particularly. 
In the two last-mentioned experiments, as the conical vessels 
were suspended in an erect position, and had a circular band or 
hoop of fine post paper, by which the lower end of each of them 
was surrounded, and which projected downwards half an inch 
below the horizontal level of the bottom of the vessel, and as the 
air which came into immediate contact with the bottom of the 
