Du Jardin, Pierre, 1620 c.
Coll. Willach Arrow right Arrow left

photo - whole telescope
Basic Info

Maker: Du Jardin, Pierre

Year: 1620 c.

Year Range: -

Year Notes:

Manufacturing Location: France [?]

Signature: PD

Signature Notes:


No stand present.

Collection: Coll. Willach

Accession #: 1699


Project investigation. Further information can be found in Bolt & Korey, "The world's oldest telescopes," in THE ORIGINS OF THE TELESCOPE (Amsterdam, 2011), pp. 237-8.

Public Notes:

Four cardboard tubes covered in blue and pink marbled paper. When collapsed forms a cylinder enclosed by end caps. Objective of 23 mm stopped down to 19 mm. Very little information known about Dujardin (1594-1645). He was known for sundials. Negative eyepiece. Both lenses held in place with spring. Paper gasket to hold in place. End rings (ferrules) made of wood. Magnification 14x.

Length (open):

Length (closed):


Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style

Physical style

Functional style

Materials: paper, pasteboard, glass, wood, leather, gold tooling

Optical/Lab Data

Drawtube data:

Drawtube notes:

Objective Data

CA curvature (diopters): CB curvature (diopters): PD lens power (diopters): fD focal length (mm): t thickness (mm): free aperture (mm): full aperture (mm): nD refractive index: ν Abbe No.:
Lens 1 670.00 23.00 19.00



Eyepiece 1
fD focal length (mm): free aperture (mm): full aperture (mm): s spacing (mm): CA curvature (diopters): CB curvature (diopters): M magnification: FOV field of view (degrees): Thickness:
Lens 1 48.00 19.00