84

REFRACTING TELESCOPES FOR ASTRONOMICAL PURPOSES.

Page 12.

Horne & Thornthwaite beg to give notice that all object glasses in the following Lists are worked under their personal superintendence, and with the assistance of their extensive series of optical tools, which they have augmented with the original tools employed by the Dollonds, and recently purchased from that firm. They can, therefore, confidently guarantee their new object glasses to be equal to any yet produced.

Telescope, with polished brass body, rack and draw adjustment to focus, achromatic finder with the necessary adjustments, dew cap, packed complete in mahogany box, and

Object Glass ... 2^-in. 3-in. 3^-in. 4-in. 42-in- 5-in. 6-in,

£7 5s- £11 £l5 ios- £22 10s. £32 £45 £71

Telescope as above, mounted on tall mahogany garden stand, and Object Glass ... 2^-in. 3-in. 3^-in. 4-in. 4^-in.

£l4 £i& £23 £34 £4$

TELESCOPE as above, mounted on tall mahogany garden stand, with horizontal and vertical screw motions, and

Object Glass ... 2£-in. 3-in. 3|-in. 4-in, 4^-in.

£l8 £2 £30 £40 £32

Telescope as above, mounted on a portable equatorial stand, with a few degrees adjustment in latitude. Hour circle, with double divisions and two verniers, declination circle, tangent screw motions to both circles, which are divided on brass, counterpoise, and requisite levels, and

Object Glass .., ... 3-in. 3^-in 4-in. 4^-in. 5-in. 6-in

£3° £40 £50 £65 £85 £103

Two forms of these instruments are manufactured—the Berthon Portable Stand, page 18, and Fig. 5, and the modified German Equatorial, page 17, and Fig. 4. Either a firm wooden tripod or an iron pillar is included.

Telescope as above, on best fixed equatorial stand, with considerable adjustment in latitude, hour circle with double divisions and verniers, declination circle, both divided on silver with reading microscopes, driving clock and independent hand motions, counterpoise and requisite levels, and

Object Glass ... ... 3^-in. 4-in. 4^-in. 5-in. 6-in.

£68 £80 £92 £110 £140

Horne and Thornthwaite will furnish special estimates for equatorially mounted telescopes of larger aperture, and for any of the above stands without the telescope. They have also thought it better not to include, eye pieces, &c., in the above prices : customers can, therefore, select those most suitable to their requirements from the list of accessories.

---

Le texte affiché peut comporter un certain nombre d'erreurs. En effet, le mode texte de ce document a été généré de façon automatique par un programme de reconnaissance optique de caractères (OCR). Le taux de reconnaissance estimé pour cette page est de 95,06 %.

La langue de reconnaissance de l'OCR est l'Anglais.

---