3B The Magnifying Power of Glajfes. 
The FOCAL DISTANCES of 
Four Magnifiers for the Microfcope 
for Opake Objects. 
o 
►—* 
P 
5 ^ 
1. 
2 . 
ICO Pts. of 
an Inch. 
Dift. of 
the Fo- 
8 
to. or 30 
y u,c x 
„ ; cas at * ^ , 
3 a i f T'S'J 0r 60 
i Inch 
4 * J 
Magnifies 
the Diam. 
— ioo - ') 
- 26 i g 
- J 3 
H 
Magnifies the 
Superficies. 
-* io, 100^ 
I 
■■■»■ '—- 676 
—— j6 9 
-- 6 4 
i w 
> a 
The magnifying Power of the Solar Mi¬ 
crofcope mu ft be calculated in fomewhat a 
different Manner. For here the Difference 
between the Focus of the Magnifier, and 
the Diftance of the Screen or Sheet where¬ 
on the Image of an Objebb is caft, is the Pro¬ 
portion ot its being magnified. Suppofe, for 
Inftance, the Lens made ufe of has its Focus 
at half an Inch, and the Screen be placed 
at the Diftance of five Feet; the Objedt 
will then appear enlarged in the Proportion 
of five Feet to half an Inch : and as in five 
Feet there are one hundred and twenty half 
Inches, the Diameter will be magnified one 
hundred and twenty Times; which, multi¬ 
plied by one hundred and twenty, fhews the 
Superficies to be magnified fourteen thou- 
fand and four hundred Times : and by put¬ 
ting 
