PHILADELPHIA 
flcDromatic Objectives 
SUPPLIED WITH LISTED OUTFITS. CORRECTED FOR COVER GLASSES, 
OF 0-16 MM. THICKNESS (No. 2) 
Equivalent Focus. 
Initial 
IN U. 
A nprtiirp 
Magnifica- 
tion. 
Price. 
Inches. 
Millimeters. 
2000 
3 
75 
Dry. 
0-8 
3 3 
$6 00 
2002 
2 
50 
O'lO 
5 
6 00 
2004 
I* 
37 
0-I4 
6-8 
6 00 
2006 
I 
25 
o-i8 
10 
6 00 
2008 
i 
17 
0-25 
15 
6 00 
2010 
1 
2 
12-5 
0 36 
20 
8 00 
2012 
i 
6-3 
077 
40 
10 00 
2014 
1. 
5" 
0-82 
50 
12 00 
2016 
1 
4-2 
0-82 
59 
12 00 
2018 
3"2 
0-85 
78 
12 00 
2020 
1 
1 0 
Oil 
Immersion. 
1-25 
100 
30 00 
2022 
2024 
1 
TI 
1 
J'S 
- 1 
1-6 J 
1-32 
1-32 
119 
156 
38 00 
54 00 
Fitting Iris diaphragm to objectives for work in photo-micrography . . • $6 OO 
epepleces 
of Huyghenian construction, supplied with all stands. They have been recently 
recomputed, making the focal plane correspond with the upper end of the tube, 
the image remaming in focus regardless of the change of, eyepiece. The optical 
tube length, therefore, remains constant, an important feature in estimating the 
magnifying power of the combinations. 
The field is large and flat, giving excellent definition, extreme care being 
employed in making and fitting every part. The eye lens is so mounted as to 
prevent disturbing reflections. They are corrected. for 160 'o mm. tube length. 
Equivalent Focus. 
Magnifica- 
Cat. No. 
tion. 
Price. 
Inches. 
Millimeters. 
Diameters. 
2026 
2 
50 
5 
$2 00 
2028 
37 
7 
2 00 
2030 
I 
25 
10 
2 00 
2032 
4 
18 
14 . 
2 00 
2034 
h 
12-5 
20 
2 00 
27 
