On HYGROMETERS. 55 
get itin again, during my ftay there, which was eighteen 
months. I brought it with me to Europe, but left the cafe 
as ufelefs, imagining that I fhould find the continental air 
of France as dry as that of Pennfylvania, where my mag- 
net box had alfo returned a fecond time to its narrownefs, 
and pinched the pieces, as heretofore, obliging me too, to 
fcrape the fealing-wax off the ends of the fhutter. 
I had not been long in France, before I was furprifed to 
find, that my box was become as large as it had always been 
in England, the magnets entered and came out with the fame 
freedom, and, when in, I could rattle them againft its fides ; 
this has continued to be the cafe without fenfible variati- 
on. My habitation is out of Paris diftant almoft a league, 
fo that the moift air of the city cannot be fuppofed to have 
much effect upon the box. 1am ona high dry hill in a 
free air as likely to be dry as any air in France. Whence 
it feems probable that the air of England in general may 
as well as that of London, be moifter than the air of Ame= 
rica, fince that of France is fo, and in a part fo diftant from 
the fea. 
The greater drynefs of the air in America appears: from 
fome other obfervations. ‘The cabinet work formerly fent 
us from: London, which confifted in thin plates of fine 
wood glued upon fir, never would fland with us, the van- 
eering, as thofe plates.are called, would get loofe and come: 
off; both woods fhrinking, and their grains often crofling, 
they were forever cracking and flying. And in my elec- 
trical experiments there, it was remarkable, that a maho- 
gany table on which my jars ftood under the prime con- 
dudtor to be charged, would often be fo dry, particularly 
when the wind had been fome time at north-weft which 
with us is a very drying wind, as to ifolate the jars, and 
prevent their being charged till I had formed a communi- 
cation between their coatings and the earth. I had a like 
table in London which I ufed for the fame purpofe all the: 
time I refided there; but it was never fo dry as to refufe: 
conducting the electricity. Nowe 
