photo - whole telescope

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 #: RW 184 [26184 / 16184] [2006 49] [2023]

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:

Objective type: singlet

Optical style astronomical

Physical style

Functional style

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

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: