Unknown, 1700 c.
National Maritime Museum Arrow right Arrow left

photo - whole telescope
Basic Info

Maker: Unknown

Year: 1700 c.

Year Range: 1675-1740

Year Notes:

Manufacturing Location: France / Italy


Signature Notes:


No stand present.

Collection: National Maritime Museum

Accession #: NAV1496


Royal Museums Greenwich. "HAnd-held telescope". http://collections.rmg.co.uk/collections/objects/43708.html [Accessed: June 2016].

Public Notes:

Museum notes suggest dating of 1740. However, materials and marbling are consistent with dating to late 17th century. Mahogany barrel with ivory fittings. Small objective, hardly stopped down. 2 of 3 eyepiece lenses survive.

Objective Notes:
Focal length measured directly in collimated beam. Eyeside inaccessible. Comparison of measured starside curvature with measured focal length implies objective is slightly biconvex, with eyeside flatter.

Eyepiece Unit Notes:
Eyepiece consists of two components. The outer tube is covered with green vellum, the inner with marbled paper. The inner tube, placed starside, contains the field lens and erector; the outer includes the ocular.


Museum note: "A label attached to the telescope indicates that it was shown at an exhibition of scientific instruments held at the Musée des Arts Décoratifs in Paris in 1936. A number of objects now held by the National Maritime Museum were shown in this exhibition, including NAV1497".

Length (open): 1092

Length (closed): 885


Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style terrestrial

Physical style

Functional style

Materials: wood, ivory, vellum, glass, pasteboard, ebony, lignum vitae, mahogany

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 1 443.27 1140.99 1.64 610.00