which would be more nice, were the Index faftened to 
the center of thelaft pully. An experiment very obvi- 
ous, but not taken notice of (as I know J by any writer, 
and fo I thought it not impertinent to be mention d 
here among Hygrofcopes, But tis high time to conclude. 
I lhallonly add this advertifement that whereas in this 
experiment onlj Oyl of Vitriol \v^s imploy*d, I have rea- 
fon to think that Oyl of Sulphur per Campanam , asalfo 
Oyl of Tartar per deltquium^ and the Liquor ofFixtNitre ^c. 
may fucceed as well,* however, Sir, I muft leave the 
profecution and improvement of this and (uch like 
obfervations to perfons who have better inftruments 
and mo^e leafure for fuch matters than. 
Your humble 
Servant. 
G. 
