[ 5*5 3 
A Table of the Six Magnifiers belonging to Mr . 
Fo Ikes’ j Microfcope , calculated by an Inch Scale 
divided into an hundred Tarts, with a Compu- 
tation of their Towers , to an Eye that fees 
Objects at Eight Inches. 
Glaf- Diftance of Magnifies the Magnifies the 
fes. the Focus. Diameter. Superficies, 
i ft. . . fz of an Inch. . . 400. . . 160,000. 
-2/d. . . j-q ...... 160. . . 25,600. 
3d. . . ^-5 • • - • . IOO. . . 10,000. 
4th. . . 7 qq ... . 
5th. * 26. . . ; 676. 
6 th. ••’a' . • • . • 1 6. ... 256. 
The above Calculation fhews, that Mr. Folkess Firft 
Glafs magnifies the Superficies of an Objed Six times 
as much as the greateft Magnifier of Mr. Leeuwen- 
hoek: And that the Animalcula (a Million whereof, 
he fays, fcarce equalled the Bignefs of a Grain of 
Sand) would, if viewed with this Magnifier, appear 
as large as Sixteen Grains of Sand do to the naked 
Eye. And I cannot fuppofe but Mr. Leeuwenhoek 
had Glaffes to magnify even more than this, though 
they are not come to us. For I cannot otherwife 
conceive, how he could obferve the Animalcules in 
the Semen mafeulinum of a Flea , and of a Gnat , as 
we find he did, (Vol. IV. pag. 21, 22.) or affert, as 
he does in the ftrongeft Terms, (pag. 23.) that he 
could fee the minuteft Sort of Animalcules in Tep- 
per-water , with his Glaffes, as plainly as he could 
Swarms of Flies or Gnats hovering in the Air with 
U u u “ his 
