Cramer, Gerrit, 1725 c.25
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Photo

photo - whole telescope
Basic Info

Maker: Cramer, Gerrit

Year: 1725 c.25

Year Range: -

Year Notes:

Manufacturing Location: Groningen, the Netherlands

Signature: G. Cramer Groningae Fecit

Signature Notes:

Inscriptions:

No stand present.

Collection: Louwman Collection of Historic Telescopes

Accession #: LC 89

Sources:

Louwman, P.J.K., and Zuidervaart, H.J., "A Certain Instrument to See Far: Four Centuries of Styling the Telescope Illustrated by a Selection of Treasures from the Louwman Collection of Historic Telescopes". Wassenaar, 2009. p.98. #95.

Louwman, P.J.K., and Zuidervaart, H.J., "A Certain Instrument for Seeing Far: Four Centuries of Styling the Telescope Illustrated by a Selection of Treasures from the Louwman Collection of Historic Telescopes". Wassenaar, 2013. p.100. #89.

Public Notes:

"There are two tubes, both made of copper:one in which the objective lens is fitted and another one with the eyepiece. The two tubes can be screwed together when the telescope is used. Total length 186 cm, Ø 5.5 cm. After usage the tube with the eyepiece can be stowed in the wider tube with the objective. The (broken) objective lens is signed: ‘G. Cramer Groningae Fecit’. First half of the eighteenth century.

This is the only known refracting telescope made by the instrument maker Gerrit Stevens Cramer from Groningen. In 1731 he made a large sandstone sundial for the garden of the ‘Prinsenhof’ in Groningen (at that time the Groningen residence of the Frisian-Groningen Stadholders). Together with Wytze Foppes and Jan van der Bildt, he was oneof the ingenious persons (in Dutch: ‘vernuftelingen’) who in the early 1740s received support from Stadholder William IV of Orange-Nassau. Cramer also made a reflecting telescope and several nicely crafted microscopes. He name is on the subscription list of the Dutch translation of Smith’s well known treatise on optics, which in 1751 was published as Volkomen samenstel der Optica (1751)" (Louwman and Zuidervaart, 2013).

Length (open): 1860

Length (closed):

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style

Physical style

Functional style

Materials: glass, copper

Optical/Lab Data

Drawtube data:

Drawtube notes:

Objective Data

Eyepieces

Notes: