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u I beg of you, fir, in the moft folemn manner, 
u that you would explain thefe rules to Mr. Watfon, 
a and intreat him, that, when the trials of thefe 
“ globes and tubes fhall be made in the prefence of 
M feveral perfons, all thefe circumflances may be 
u regarded; left any thing be omitted, which may 
<c conduce to the knowledge of the truth/’ 
The tubes and globes referred to in the above let- 
ter were received by the Royal Society about the mid- 
dle of May 1751, and were prefented to that body 
by the Prefident at their next meeting ; and they 
were put into my hands, in order that their effects 
upon trial might be reported at a future meeting. 
The larged: fphere was of cryftal glafs of about 
feven inches diameter, fixed to its wooden fpindles 
by a refinous cement, and contained not more than 
half an ounce of a terebinthinate fluid, lefs deep in 
colour than balfam of Peru, and more fo than bairn 
of Gilead. The fmaller globe was five inches in dia- 
ter, was mounted nearly as the larger one, and con- 
tained about half an ounce of beaten cinnamon. The 
tube containing the flowers of fulphur was two feet 
in length, and about half an inch in diameter : it, 
like the globes and the other tubes, was of cryflal 
glafs, and in like manner with the red of the tubes 
was hermetically fealed. The tube, faid to contain 
balfam of Peru and chalk, was about twenty inches 
long, and f of an inch in diameter : that faid to contain 
opobalfamum was about fixteen inches long, and half 
an inch in diameter : and that with fpirit of wine and 
chalk was about feventeen inches long, and about 
half an inch in diameter. 
The manner of mounting thefe globes might be 
fomewhat exceptionable for the purpofes intended, 
