To he placed after Page 36. 
* A TABLE of the MAGNIFYING POWERS of CONVEX GLASSES, 
employed in Single Microscopes, according to the Difiance of their 
Focus: Calculated by the Scale of an Inch divided into an Hundred Parts: 
Shewing how many Times the Diameter , the Superficies , and the Cube of an Objedt is 
magnified , when viewed through fuch Glajfes , to an Eye whole natural Sight is at 
Eight Inches , or Eight Hundred of the Hundredth Parts of an Inch. 
Magnifies 
Magnifies 
Magnifies the 
the Dia- 
the Super- 
Cube of an 
meter, 
ficies. 
Objeffi^ 
* 
" l 9 or 
S°1 
16 
256 
4,096 
-A, or 
40 
20 
400 
8,000 
~r~o 9 or 
3 ° 
26 
676 
17,576 
t> or 
20 
40 
1,600 
64,000 
15 
x 53 
2,806 
148,877 
r 4 
c 57 
3> 2 49 
185,193 
: 
^ 61 
3 > 7 21 
226,981 
12 
§ 66 
4 . 3 s 6 
287,496 
The Focus oT 
11 
^0 72 
S ’ i8 4 
373,248 
■At, or 
10 
J-2 80 
6,400 
512,000 y Times. 
a Glafs at 
9 
1 88 
7>744 
681,472 
8 
100 
10,000 
1,000,000 
7 
CL) 
•S JI 4 
12,996 
1,481,544 
6 
§ *33 
17,689 
2 , 3 S 2 > 6 37 
tV, % or 5 
m 160 
25,600 
4,096,000 
4 
200 
40,000 
8,000,000 
3 
266 
70,756 
18,821,096 
, 1 
to, or 
2 
400 
160,000 
64,000,000 
i r 
1 1 1 "■ T".. 
i- 
Boo 
640,000 
5I2,OOO s OOO 
1 ’ 
J 
J The greateft Magnifier in Mr. Leeuwenhoek’s Cabinet of Microfcopes, prefented to the Royal Society, 
has its Focus, as nearly as can well be meafured, at one Twentieth of an Inch Diftance from its Center, and 
confequently magnifies the Diameiet of an Object 160 Times, and the Superficies 25,600. But the greateft 
Magnifier in Mr. Wilson’s Single Microfcopes, as they are now made, has ufually its Focus at no farther 
Ditiance than about the Fiftieth Part of an Inch ; whereby it has the Power of enlarging the Diameter of 
an Objeft 400, and its Superficies 160,000 Times. 
