Marshall, John, 1694
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Photo

photo - whole telescope
Basic Info

Maker: Marshall, John

Year: 1694

Year Range: -

Year Notes:

Manufacturing Location: England

Signature: John Marshall London Fecit 1694 [on objective lens]. JOHN:MARSHALL+LVDGAT: STREET+LONDON [three times on main tube].

Signature Notes:

Inscriptions:

No stand present.

Collection: Coll. Willach

Accession #: 26184 / 16184

Sources:

Project investigation

Public Notes:

Ten draws, 5500 mm long. English astronomical reverse taper. Huygens eyepiece-- unscrews from tube. The two lens eyepiece unit is friction fit and slides for magnification. Ferrules are colored, and decorated with mottling. English reverse taper tooling: some have centering lines, two stamps, one on either side of center line; others are complete, single stamps. Ornate tooling in 17c, versus florid from 1825 on.

Length (open): 5500 [?]

Length (closed):

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style astronomical

Physical style

Functional style

Materials: glass, gold leaf, wood, paper, pasteboard

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 0.18 5535.00 65.00

Eyepieces

Notes: