24 Life of Count Rumford. 



"WoeuRN, Aug ( . 1 6, 1769. 



" MR. BENJ. THOMPSON, 



" SIR, It is almost impossible to describe the directions the 

 rays pass. Suppose one was at the Equinoctial Line, at twelve 

 o'clock. At that place then I imagine that the rays of the Sun 

 would pass directly straight to the eye of the beholder. But 

 suppose the Sun to be just arising, then I imagine that the rays 

 would pass in a curve line, and so grow straighter as it rises 

 higher in the horizon. The reason is, I conjecture, owing to 

 the Vapours that ascend out of the earth. I would prove it thus. 

 Take a bowl and put a dollar in it, and then carefully filling it 

 with fair water, till it seems to be heaped as it will do if the 

 brim was dry, and go off to a distance that brings your eye level 

 with the top of the bowl, and you can see the dollar in the 

 bottom of the bowl ; and that air nigh the ground is something 

 of the same nature is the opinion of 



" Your Humble Servant, 



"LOAMMI BALDWIN." 



"WoBURN, August 1 6th, 1769. 



" MR. LOAMMI BALDWIN, 



SIR, Please to inform me in what manner fire operates 

 upon Clay, to change the Colour, from the Natural Colour to 

 red, and from red to black, &c. ; and how it operates upon 

 Silver, to change it to Blue. 



" I am your most Humble, and Obedient Servant, 



"BENJ> THOMPSON. 

 "God save the King." 



" WOBURN, Aug 1 . 1769. 



" MR. LOAMMI BALDWIN 



SiR, Please to give the Nature, Essence, Beginning of 

 Existence, and Rise of the Wind in General, with the whole 

 Theory thereof, so as to be able to answer all Questions relative 



thereto. 



" Yours, 



"BENJ. THOMPSON." 



