van Deijl, Jan and Harmanus, 1768
Louwman Collection of Historic Telescopes Arrow right Arrow left

photo - whole telescope
Basic Info

Maker: van Deijl, Jan and Harmanus

Year: 1768

Year Range: -

Year Notes:

Manufacturing Location: the Netherlands

Signature: Jan van Deijl en Zoon Inv. et Fec, Amsterdam, 1768

Signature Notes:


No stand present.

Collection: Louwman Collection of Historic Telescopes

Accession #: LC 164


Cocquyt, Tiemen "400 Years of Telescopes" booklet, Zeeuws Museum, 2008. Item 20.

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. 147. #164.

Public Notes:

"Achromatic brass pocket telescope, signed: ‘Jan van Deijl en zoon Inv. et Fec, Amsterdam, 1768’. The eyepiece can be unscrewed, reversed and then stored in the main tube. Maximum length 25 cm, Ø 2.5 cm" (Louwman and Zuidervaart, 2013).

Brass construction. Jan van Deijl produced achromatic telescopes with his son Harmanus for the Dutch market until around 1800s. van Deijl worked with the brass founder Carl Ulrich Bley, who reverse-engineered the method for creating achromatic lenses by studying Dollond's telescopes.

Length (open): 250

Length (closed):


Exit pupil:

Object status:

Optical Basics

Objective type: unconfirmed

Optical style

Physical style pocket

Functional style

Materials: brass

Optical/Lab Data

Drawtube data:

Drawtube notes:

Objective Data