( 74 ? ) 
It might now be fliown, how naturally the various, 
and -feemingly contrary appearances of the above 
mention’d Experiments are deducible from this Theory^ 
but this- is (6 ealy, .that it is needlefs to infifl; upon it ; 
and our difcourfe upon this minute Subjed: has been 
already lb tedious, that we could fcarce hope for Pardon, 
unlefs it were direded to thofe, who are fenfible to 
how many of the greater, and more iconfiderabie, Phte* 
nomena of Nature this 'Dodrine is applicable. 
■ ‘ e ■ 
P 5. When this i Paper was* reading "before. the So- 
ciety, I found that our incomparable PreTident. was 
already acquainted with the above-mentioned Prindplo, 
and 1^ have fmcemet with feveral PalTages in the..} i(t 
Query fubjoin’d to the late'* Edition of his Opticks 
wh^h plainly Ihevv/ that he was Mailer of it, when 
they were written. ‘ * - •• . 
1 mud do the fame Judice to that excellent Mathema- 
tician Mr. ^ohn Maihinf Profeflbt of Adronomy in 
6 refham College. i j > 
To thefe two worthy Perfons l am obliged for the 
following Obfervatioii,'’ That, what 1 call a Periphery, 
or Sedion of the concave fur^ce of the Tube, is really 
a fmall Surface, whole Bale. is chat Periphery, and 
whofe height is the didance, to which the aettadive 
power of the Glafs is extended. r 
IIL Tk 
• • 
C c c c< c 
