| £ | s. | d. | |
| 5-1/4 inch Speculum from 4 to 6 feet focus, with 8 inch hour circles reading to 5 seconds of time, and declination circle reading to 1 minute, two powers | 30 | 0 | 0 |
| 6-1/2 inch Speculum of from 5 to 6-1/2 feet focus, 10 inch rotating hour circle, reading to 5 seconds of time, and declination circle to 1 minute of arc, with 3 powers—100 to 500 | 45 | 0 | 0 |
| 8-1/2 inch Speculum as above with 12 inch circles, 4 powers | 70 | 0 | 0 |
| 9-1/4 inch Speculum as above with 12 inch circles, 5 powers | 78 | 0 | 0 |
| 10 inch Speculum as above with 12 inch circles, 5 powers | 90 | 0 | 0 |
| 12-1/2 inch Speculum as above with 12 inch circles, 5 powers | 120 | 0 | 0 |
Any of the above sizes mounted on Stand (Fig. 1), from 5 per cent. extra.
Fig. 1 is a very excellent stand, and admirably suited for large instruments with clock power, and is convenient to remove and adapt to different latitudes, &c., see [p. 20.]
| £ | s. | d. | ||
14, 15, to 16 inch Speculum mounted as (Fig. 1), with rotating hour circle reading to 5 seconds and declination to 1 minute (the diameter of the circles never less than that of the Speculum and often larger) | ||||
8 powers from 50 to 700, with first-rate and very powerful drivingclock, first-class instrument, and complete | from £220 to | 330 | 0 | 0 |
17, 18, to 20 inch Speculum, with 10 powers, from 50 to 800, includingKellners, Huyghenians, and Achromatics, | from £350 to | 500 | 0 | 0 |
22 to 24 inch Speculum | from £550 to | 750 | 0 | 0 |
30 inch Speculum, with 12 powers and position micrometer, andtransit eye-pieces | 1000 | 0 | 0 | |
Prices will be forwarded for special arrangements in any of these large sizes.
The Cassegrain Telescope is a very convenient form, and perfect in performance, and in this form a very large instrument requires comparatively a much smaller observatory, and is more conveniently worked. They can be made so that the image is thrown out at the side and viewed diagonally, as with the Newtonian, see [p. 35.] Cassegrains from 5 per cent. extra.
| £ | s. | d. | ||||||
| Driving | Clocks for | 6 | to | 10 | inch | 35 | 0 | 0 |
| 〃 | 〃 | 12 | 〃 | 18 | 〃 | 40 | 0 | 0 |
| 〃 | 〃 | 20 | 〃 | 30 | 〃 | 50 | 0 | 0 |
The Educational Reflector is a plain and very steady and satisfactory instrument, mounted on (Fig. 2) stand, without circles, has revolving body, and made so as to be portable.
| £ | s. | d. | |
| 6-1/2 inch Speculum (clear aperture), and of 4 to 6-1/2 feet focus, has screw-motion in right ascension, 2 powers | 25 | 0 | 0 |
| 8-1/2 inch speculum as above, with 3 powers | 40 | 0 | 0 |