REFLECTING TELESCOPE - JAN VAN DEN BILDT FRANEKER CA 1745-1760

A charming brass reflecting telescope of Dutch make.
The Gregorian reflecting telescope, named after the Scottish mathematician James Gregory, has a hollow objective mirror
and a hollow second mirror, which reflects the light of the object-glass to the eyepiece through a hole in the middle of the object mirror.
Focussing is done by moving the secondary mirror by means of a setscrew attached to the brass tube.
The optical system and focus mechanism are in excellent condition.
Most of the time the instrument has been kept in a cedar wood box en that is partly the reason it has remained smooth.
If you want to look at the moon, planets or nebulas, you can do so with this historical telescope.
All lenses and mirrors are present.
Height 35 cm. (13.5 inches)
Length 42 cm. (16.5 inches)
Tube diameter 7 cm. (3 inches)
Jan van den Bildt was the foremost Dutch manufacturer of reflecting telescopes.

SOLD

18TH CENTURY VELLUM AND SHAGREEN TELESCOPE

Telescope consisting of five parts; the first tube part is made of cardboard fitted with pretty green shagreen leather.
The four extending tube parts are made of green vellum.
On some tube parts stoplines are applied to mark optimum working length.
Closed: ca 30 cm (12 inches).
Opened up to the stoplines: 105 cm (41.5 inches).
The telescope is equipped with a sliding eyepiece cover.
The object lens is 1.5 inches in diameter and is sealable with a brass screw cap.
Made around 1770 by John & Pieter Dollond of London.
The largest tube bears a mark: Dollond London.

SOLD TO THE USA

DOLLOND TELESCOPE OF SHAGREEN LEATHER CA. 1790 – 1800

A distinct and handsome telescope by the Dollond firm from the late 18th century.
The lens barrier has the 18th century signature of John Dollond of London with wide graceful flourishes.
An elegantly shaped eyepiece with a big object-glass, also equipped with a retractable hood.
The telescope has two retractable tubes and is beautifully finished with light green shagreen leather.
Length closed 40 cm.
Length open 80 cm.

SOLD