Gilbert, J.
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Photo

photo - signature
Basic Info

Maker: Gilbert, J.

Year:

Year Range: 1745-1791

Year Notes:

Manufacturing Location: London, England

Signature: J. GILBERT / Tower Hill / LONDON

Signature Notes:

Inscriptions:

No stand present.

Collection: Coll. Willach

Accession #: 12

Sources:

Project investigation

Public Notes:

Five lens eyepiece. Crown forward (front lens of achromat) has same surface curvature as Dollond crown lens but the flint lens has a different curvature. Maker might thus have purchased lens from Dollond. After Fraunhofer, eyepiece lenses are calculated surfaces. Before then, makers such as Dollond used trial and error.

Length (open):

Length (closed):

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: doublet (crown forward)

Optical style

Physical style polygonal

Functional style

Materials: wood, brass, glass

Optical/Lab Data

Drawtube data:

Drawtube notes:

Objective Data

Eyepieces

Notes: