PHILADELPHIA 
masnfflers, etc. 
The Hastings Aplanatic Triplets, computed after a new formula, have large 
angolar fields are free from color errors and have a long working distance. 
The series has been designed from the new optical glasses. For use as a pocket 
lens, the powers 6.7 and 10 are especially recommended, the first, perhaps, superior 
in general utility, and the second a more convenient size. The lenses are mounted 
in a very neat case of German-silver. When desired for the dissecting micro- 
scope, they will be furnished in suitable mounting without extra cost. 
Hastings Aplanatic Triplet 
The finest grade of pocket lens 
focal length. 
NO. 
magnification. 
real field 
price. 
MM. 
Inches. 
Mm. 
2098 
5 
2 
51.0 
40.0 
$7 00 
2100 
6.7 
38.0 
30.0 
7 00 
2102 
10 
I 
25.0 
20.0 
7 00 
2104 
15 
a 
4 
19.0 
14.0 
7 00 
2106 
20 
13.0 
7-5 
7 00 
2108. Reiading Glasses, nickel plated rims and black enameled wood handle. 
Diam. oflens, 2 2J 3 3I 4 4J 5 6 inches. 
Price, each, $0.80 l.OO 1.50 2.00 2.50 3.25 4.00 5.00 6.0O 
2110. Reading Glasses, gold-plated rims, white or oriental pearl handles. 
Diam. of lens, 2J 3 3i 4 4? 5 5^ 6 inches. 
Price, each, $3.00 3.50 4.00 5.00 6.00 7.00 8.50 10.00 
35 
