8 powers from 50 to 700, with first-rate and very powerful driving clock, first-class instrument, and complete from £220 to 330 0 0
17, 18, to 20 inch Speculum, with 10 powers, from 50 to 800, including Kellners, 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, and transit 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
Any of these equatorials can be, according to wish, fitted without the circles, &c., and dispensing with that which is not needed, so as to reduce the price to suit circumstances and convenience.
The POPULAR REFLECTOR, with Angle-Block Stand, with endless screw-motion to follow the stars with equatorial motion.
£ s. d. 5-1/4 inch Speculum, of from 4 to 6 feet focus, with 2 powers 15 15 0
Reflecting Telescope on Alt-azimuth Stand, as described at page 13, fitted with Silvered Glass Speculum, and provided with Two Eye-pieces.
£ s. d. 5-1/4 inch Speculum, 4 to 6 feet focus 19 10 0 6-1/2 〃 〃 4 〃 6-1/2 〃 24 0 0 8-1/2 〃 〃 〃 6-1/2 〃 33 10 0 10 〃 〃 〃 7 〃 45 0 0 12-1/2 〃 〃 〃 8 〃 70 10 0
Reflecting Telescope on Cradle Stand, and provided with Two Eye-pieces.
£ s. d. 5-1/4 inch Speculum, 4 to 6 feet focus 21 0 0 6-1/2 〃 〃 4 〃 6-1/2 or 5 feet focus 27 0 0 8-1/2 〃 〃 〃 6-1/2 〃 〃 36 0 0 10 〃 〃 〃 7 〃 〃 49 0 0 12-1/2 〃 〃 〃 8 〃 〃 76 0 0
£ 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