( 40 ) 
being fo many Degrees fofter than thofe of any o- 
ther Metal. 
^^lery II. . I have often found the touching Sur- 
’'faces" of fuch ^ Leaden Balls, as near as I could mea- 
fure, much ‘alike; *yet the Force of Cohefion very 
different : Nay, J have found the touching Surfaces 
very fmall, yet fometimes 114 to ii6ft Weight has 
not been fufhcient to feparate them , when at other 
Times a far lefs Weight (though the Meafure of 
touching Surfaces far exceeded thofe mentioned ) was 
more than fufhcient to caufe their Separation, . Does 
it not prove that the Cohefion is ftrongeft according 
to the clofenefs of the Contad,. but not as the touch- 
ing Surfaces ? For which Reafon I always have found 
the Cohefion ftrongefl, when I gave a little twifl in 
joining them \ fince by this Means the Particles imift 
come clofer together, than by fqueezing the Balls 
barely on one another, though it was done with a 
far greater Force than I could apply with my bare 
Hands. And fince the Force, Twift, and touching Sur- 
faces can never be alike and menfurable when joined 
by Hand, I think it will be very difficult, if not 
irapoffible to afcertain the Forces of this Cohefion^ 
which is incredible, and far exceeds Magnetical At- 
traftions. 
That the Preffure of the Atmofphere contributes 
little,, and next to nothing in this Cohefion, I have 
fully proved and experienced laft Winter, before a 
great and noble Affembly at my Ledures". held in 
this Place : The Cohefion of two Leaden Balls, which 
ii6 lb could not feparate, prov’d as Itrong in Facuo^ 
as in the open Air. 
^lery 
