114, Count Romford’s Enquiry concerning the Nature of Heat , 
the bubble of spirit of wine remaining immoveably in the same 
place. 
Exper. No. 17. Having assured myself, by these previous 
trials, that the instrument was not sensibly affected by a bright 
metallic surface being presented to it, provided the tempera- 
ture of the metal and that of the instrument were the same, I 
now withdrew one of the cylindrical vessels, and, taking it into 
another room, I filled it with pounded ice and water. 
Entering the room again, I now presented the flat vertical 
bottom of this horizontal cylindrical vessel, filled with ice and 
water, to one of the balls of the thermoscope, at the distance of 
four inches. 
The bubble of spirit of wine began instantly to move, with a 
slow regular motion, towards the cold body ; and, having ad- 
vanced in the tube about an inch, it remained stationary. 
On bringing the cold body nearer the ball to which it was 
presented, the bubble was again put in motion, and advanced 
still farther towards the cold body. 
Exper. No. 18. Although the result of the foregoing experi- 
ment appeared to me to afford the most indisputable proof of 
the radiation of cold bodies, and that the rays which proceed 
from them have a power of generating cold in warmer bodies 
which are exposed to their influence, yet, in a matter so extremely 
curious, and of such high importance to the science of heat, I 
was not willing to rest my enquiries on the result of a single 
experiment. 
In order to vary the substance, or species of matter, presented 
cold to the instrument, and, at the same time, to remove all 
suspicion respecting the possibility of the effects observed being 
