(6o) 
ehailge the Center ; and that the Glafs is not preffcd at the fame 
time by the Ring but in one part on the fidej vid, about a fourth; 
and that the parts of the Glafs are not equally worn away, (^c. 
What theUj faith he, would becomof a Glafs of locoo feet, 
which, according to the faid Table, would have more than four 
feetj or four feet and nine inchcsj or five feetj feven inches ^- 
ferture.and of which the 7^2«g,though it were two feet nine inch- 
es, would have but one minut of Inclination, and the Glafs of f 
feet Jprture would have but 4 minuts, and the curvity of it 
would be lefs than the hundred part of a Line. 
But,/aith he, let us confider, only a Glafs of 3O0 foot?, to fee^ 
whatis tobe hoped ofthat, and toknow at leaft the difficulty, 
to be met with in making a Glafs only of that Length. A Glafs 
then of 5C0 foot, according to his Tabkj mufl: have more than 
8^ inches aperture, which maketh but J 6 minuts of its Circle^ and 
it fliould have more than 1 1 inches, if it be an excellentone; 
If Mr. Ho^k^ ( adds he ) did ufe but his l^ifig of 6 inches, which 
he would ufe from twelve to an hundred foot Glafs , the IncJu 
nation ^ which the Axis, or Mandril, that bears his Glafs, fliould 
have, fhould be but 16 minuts, and the ta^rz^i/y of the Glafs 
would be lefs than the eightli part of a Line , and if he fliould 
life a bigger, the Inclination would be proportionable. 
Whence it may be judged ( continues he) that we are yet 
very far from feeing Animals &p, in the Mcon^ as Monfieur Des 
Cartes gave hope, and Mr. Hoo\ defpairs not of. For , he be- 
lieves by what he ktiows oi Tele/copes^ that we are not to look 
for any above goo or 400 foot at moft 1 and he fears^ that nei- 
ther Matter nor Art will go even fo far. 
When therefore {faith he^ a Glafs of 300 foot fhould bear 
an Eye-g!afs of <5 inches (which would appear wonderful) it 
would magnifie but (^oo. times in Biameter^Ah^it is^ ^60000 
times in Smface-, but fuppofe^that fuch couid be made,as would 
magnifie a loco times in Diameter^ and loooooo. of times in, 
Surface, admitting there were but doooo leagues from the Earth 
to the Moon, and that the fmalnefs ofthe y^/^r^^r^ of the Glaf* 
fes ( which yet would diminifli the Light more than 36 times) 
and the obftacie of the Air were no t confidered, we fliould iict; 
ice.; 
