Dioptrice : pre-1775 refracting telescopes

pre-1775 refracting telescopes

e.g. “dollond”

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Watkins, Francis, 1780 c.
National Maritime Museum

Photo

photo - whole telescope

Basic Info

Maker: Watkins, Francis

Year: 1780 c.

Year Range: -

Year Notes:

Manufacturing Location: London, England

Signature:

Signature Notes:

Inscriptions:

Stand present.

Collection: National Maritime Museum

Accession #: AST0959

Sources:

Royal Museums Greenwich. "Portable reflector telescope". http://collections.rmg.co.uk/collections/objects/11121.html [Accessed: June 2016].

Public Notes:

Length (open):

Length (closed):

F-ratio:

Exit pupil:

Object status:

Optical Basics

Objective type: gregorian

Optical style

Physical style

Functional style

Materials: brass, glass

Optical/Lab Data

Drawtube data:

Drawtube notes:

Objective Data

Eyepieces

Notes:

Wavelength	Paraxial	70%	Whole
652	±	-0.7 ± 0.2 ±	±
575	±	0 ±	±
482	±	-1.0 ± 0.2 ±	±

Additional Photos/Documents

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Dioptrice is made possible by the generous support of the National Science Foundation, the National Endowment for the Humanities, the Program in the History and Philosophy of Science at the University of Notre Dame, and the Adler Planetarium & Astronomy Museum.

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+ Objective type:	(all refractors) (all reflectors) (clear selection) N/A cassegrain doublet (crown forward) doublet (flint forward) doublet (unknown) gregorian herschelian newtonian singlet triplet unconfirmed unknown reflector

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Objective Data

Eyepieces