(6o) 
change the Center s and that the Glafs is not preffed at the fame 
time by the Ring but in one part on the fide,wi. about a fourth} 
and that the parts of the Glafs are not equally worn away, (£e. 
What then, faith be, would becomof a Glafs of ioooo feet, 
which, according to the faid Table, would have more than four, 
feet, or four feet and nine inches, or five feet, feven inches A - 
perture, and of which the Ring, though it were two feet nine inch- 
es, would have but one minut of Inclination , and the Glafs of y 
feet Aperture would have but 4 minuts, and the curvity of it 
would be lefs than the hundred part of a Line. 
But, faith he, let 11s confider, only a Glafs of 300 foot, to fee r 
what is to be hoped of that, and. to know at leaft the difficulty, 
to be met with in making a Glafs only of that Length. A Glafs 
then of 300 foot, according to his Table, muft have more than 
8 inches Aperture , which maketh but 16 minuts of its Circle , and 
it fliould have more than 1 1 inches, if it be an excellent one. 
If Mr. Moo\_ ( adds he ) did ufe but his Ring of 6 inches, which 
he would ufe from twelve to an hundred foot Glafs, the Incite 
nation 3 which the Axis , or Mandril, that bears his Glafs, fhould 
'have, fliould be but 16 minuts , and the Curvity of the Glafs 
would be lefs than the eighth part of a Line , and if he fliould 
ufe a bigger, the Inclination would be proportionable. 
, Whence it may be judged ( continues he) that we are yet 
very far from feeing Animals &c. in the Moon, as Monfieur Des 
Cartes gave hope, and 1tAr;Hoo\ defpairs not of. Tor , he be- 
lieves by wha.t he knows of Telefcopes^ that we are not to look 
for any above goo or 4oofootatmoft j and he fears, that nei- 
ther Matter nor Art will go even fo far. 
When therefore ( faith he ) a Glafs of 300 foot fliould bear 
an Eye-glafs of 6 inches (which would appear wonderful) it 
would magnifie but 600. times in Diameter 5 that is, 360000 
times in Surface : but fuppofe,that fuch could be made, as would 
magnifie a roco times in Diameter , and iooooco. of times in 
Surface , admitting there were but 60000 leagues from the Earth 
to the Moon, and that the fmalnefs of the Aperture of the Glafi 
fes ( which yet would diminish the Light more than 36 times ) 
md the ofeftade of the Airwer® not confidered, we fliould not 
fee, 
