Mann & Ayscough
Adler Planetarium and Astronomy Museum Arrow right Arrow left

Basic Info

Maker: Mann & Ayscough


Year Range: 1743-1747

Year Notes:

Manufacturing Location: England


Signature Notes:


No stand present.

Collection: Adler Planetarium and Astronomy Museum

Accession #: W-283


Project investigation and collection website.

Public Notes:

Objective cell screw into slider cap, and cap into draw.
Similar to M-455 but 3 rather than 5 lenses.
Small objective.
Shaved rayskin pattern (shagreen), with rouge filling spaces between cells. Objective has slider, brass cell.
Draws have wooden aperture stops at objective end, milled brass ferrules at ocular end.
Covered in green vellum.
Inked, dotted extension marks.
3 draws.
Ocular unit with 3 lens erector.

Length (open):

Length (closed):


Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style

Physical style spyglass

Functional style

Materials: vellum, shagreen, pasteboard, wood, glass, brass

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 2.40 ± 0.002 417.60 ± 0.4



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 37.40
Lens 2 37.70
Lens 3 37.90