14 
List of the Apochromatic Objectives. 
Numerical 
aperture 
Equivalent 
focus in mm 
Initial 
magnification 
Price 
Marks 
Dry Series 
0.30 
24.0* 
16.0 
10.5 
15.5 
140.— 
100.— 
0.65 
12.0* 
8.0 
21 
31 
170 — 
130 — 
0.95 
6.0* 
4.0 
3.0 
42 
63 
83 
220.- 
180- 
200.— 
with"' cor- 
rection collar 
Water Iinniersion 
1.25 
2.5 
100 
300.- 
with cor- 
rection collar 
Homogeneous 
Immersion 
1.30 
3.0 
2.0 
1.5 
83 
125 
167 
400 — 
400 — 
450 — 
1.40 
3.0 
2.0 
83 
125 
500.- 
500.— 
Monobromide of 
Naplitlialine Immersion 
1.60 
2.5 
100 
800.— 
The last named system is supplied together with 25 fiint cover-glasses and 
3 slips of heavy flint. 
Each additional cover-glass M. 1. — 
Each additional slip , 2. — 
Noii-acbromatic Condenser of 1.60 aperture having a flint-glass front-lens 
to be used with the monobromide of naphthaline immersion lens (for very oblique 
or wide illuminating pencils) . . . M. 35. — 
Monobromide of Naphthaline, per bottle containing 5 gr . . ,, 1.50 
* The three objectives 24-mm, 12-m,m and 6-mm of the dry 
series are constructed exclusively for the 10-inch tuhCf all the 
others are adjusted either for continental or English tube. 
