THE FINEST QUALITY GUARANTEED.
| £ | s. | d. | ||||||
| 5-1/4 | inch diameter, | 4 | to | 6 | feet focus | 5 | 0 | 0 |
| 6-1/2 | 〃 | 4 | 〃 | 6-1/2 | 〃 | 6 | 5 | 0 |
| 8-1/2 | 〃 | 〃 | 6-1/2 | 〃 | 13 | 0 | 0 | |
| 10 | 〃 | 〃 | 7 | 〃 | 25 | 0 | 0 | |
| 12-1/2 | 〃 | 〃 | 8 | 〃 | 38 | 10 | 0 | |
| 14 | 〃 | 〃 | 8 | 〃 | 55 | 0 | 0 | |
| 16 | 〃 | 〃 | 10 | 〃 | 75 | 0 | 0 | |
| 18 | 〃 | 〃 | 12 | 〃 | 100 | 0 | 0 | |
| 20 | 〃 | 〃 | 12 | 〃 | 130 | 0 | 0 | |
| 22 | 〃 | 〃 | 15 | 〃 | 165 | 0 | 0 | |
| 24 | 〃 | 〃 | 18 | 〃 | 200 | 0 | 0 | |
| 26 | 〃 | 〃 | 〃 | 250 | 0 | 0 | ||
| 30 | 〃 | 〃 | 〃 | 300 | 0 | 0 | ||
| 36 | 〃 | 〃 | 〃 | 400 | 0 | 0 | ||
Silvered-Glass Diagonal Mirrors (unmounted).
FINEST QUALITY GUARANTEED.
| £ | s. | d. | ||
| 1 inch | in the minor axis, or narrowest diameter of the ellipse | 1 | 0 | 0 |
| 1-1/2 | dittodittoditto | 1 | 10 | 0 |
| 2 | dittodittoditto | 2 | 0 | 0 |
| 2-1/2 | dittodittoditto | 2 | 10 | 0 |
| 3 | dittodittoditto | 3 | 3 | 0 |
| 3-1/2 | dittodittoditto | 4 | 4 | 0 |
| 4 | dittodittoditto | 5 | 5 | 0 |
Silvering and Polishing Specula.
| £ | s. | d. | |||
| 5 | inch | 0 | 6 | 0 | |
| 6-1/2 | 〃 | 0 | 8 | 0 | |
| 8-1/2 | 〃 | 0 | 10 | 6 | |
| 10 | 〃 | 0 | 15 | 0 | |
| 12-1/2 | 〃 | 1 | 1 | 0 | |
| Diagonal Planes 3s. to | 0 | 5 | 0 | ||
ASTRONOMICAL EYE-PIECES.
OF BEST QUALITY.
Huyghenian Construction of the following magnifying powers on a 6-1/2 feet focus object-glass:—