( 10 ) 
GREATLY REDUCED PRICES 
OF 
OBJECT-GLASSES MANUFACTURED BY 
R, & J. BECK, 
68, CORNHILL, LONDON, E.C. 
PfilCES OF BEST ACHROMATIC OBJECT-GLASSES. 
Angle 
of 
aper- 
Linear magnifying-power, with 
1 lo-inch 
No. 
Focal length. 
Price. 
body-tube and eye-pieces. 
ture, 
No. 1 . 
No. 2 . 
p 
to 
1 No. 4. 
No. 5. 
about 
Q 
£ 
s. 
d. 
100 
4 inches 
9 
1 
16 
0 
10 
16 
30 
40 
50 
101 
3 inches 
7 
1 
10 
0 
} - 
24 
45 
60 
102 
3 inches 
12 
2 
10 
0 
75 
103 
2 inches 
lO 
1 
10 
0 
} » 
36 
67 
90 
112 
104 
2 inches 
17 
2 
10 
0 
105 
1 ^ inch . . 
23 
2 
10 
0 
30 
48 
90 
120 
150 
106 
107 
1 inch . . 
1 inch . . 
25 
32 
2 
2 
0 
10 
0 
0 
} 70 
112 
210 
280 
350 
108 
j inch . . 
45 
2 
10 
0 
100 
160 
300 
400 
500 
109 
^ inch . . 
65 
4 
0 
0 
125 
200 
375 
500 
625 
110 
■fo ii^ch . . 
1 inch . . 
95 
5 
0 
0 
150 
240 
450 
600 
750 
111 
75 
3 
10 
0 
200 
320 
600 
800 
1000 
112 
L inch . . 
120 
4 
10 
0 
250 
400 
750 
1000 
1250 
113 
A inch . . 
130 
5 
0 
0 
400 
640 
1200 
1600 
2000 
114 
^imra. 
180 
5 
5 
0 
500 
800 
1500 
2000 
2500 
115 
•jL imm. 
180 
8 
0 
0 
750 
1200 
2250 
3000 
3750 
116 
^imm. 
180 
10 
0 
0 
1000 
1600 
3000 
4000 
5000 
117 
^ inch . . 
160 
20 
0 
0 
2000 
3200 
6000 
8000 
10,000 
ECONOMIC ACHROMATIC OBJECT-GLASSES, 
Applicable to all Instruments made with the Universal Screw. 
! 1 
No. 
Focal length. 
Angle 
of 
aper- 
ture, 
about 
! 
Price. 
Magnifying-power, i 
with 6-inch body and ; 
eye-pieces. j 
1 
No. 1. 
No. 2. 
No. 3. 
0 
i £ 5. 
d . 
150 
3 inches 
6 
1 0 
0 
12 
15 
27 
151 
2 inches 
8 
1 0 
0 
18 
23 
41 
152 
1 inch 
18 
1 5 
0 
46 
61 
106 
153 
^ inch 
38 
1 5 
0 
90 
116 
205 
154 
1 inch 
80 
1 5 
0 
170 
220 
415 
155 
i inch 
1 10 
2 5 
0 
250 
330 
630 
156 
inch 
no 
3 10 
0 
350 
450 
800 
157 
■A imm 
180 
6 0 
0 
654 
844 
1500 
Revised Catalogue sent on application to 
R. & JT. BJElCKs 08, Coi'nliill, 
