Day or Night

Single Draw Telescope

Barry Minories, London

© Brooke Clarke 2024

Day or Night Single Draw Telescope Day or Night Single Draw Telescope

Background
Description
    Day or Night
        Specifications
    Officer of the Watch
Photos
Drawing
Patents
Related
References
Links

Background

Povenance

This was owned by sea captain George Gibbs (1800 - 1858) and has been in his family for about 100 years.

This Day or Night single draw telescope was made by Barry on Minories St., London.  The same design was also made by Dollond & Aitchison (Wiki), Doland (Wiki), London; T. Harris & Son, London; Richardson, London; Watkins & Hill, Charing Cross London; George Dixey, London made a triple draw version.

Description

This is a single draw telescope where the main body is made of wood and the draw tube is metal.  The draw tube has a smaller tube mounted inside which in turn contains a couple of lenses.  The eyepiece is made up of two lenses.

The design is a microscope looking at the objective image. (Ref 1.)  That's interesting since modern "infinity tube" microscopes are astronomical telescopes looking at a collimated image from the objective, (Nikon infinity SMZ head).

Huygens (Wiki) type eyepiece.

Day or Night

The "Day or Night" nomenclature comes about because it is possible to remove the erecting lens assembly that's used for right side up terrestrial daytime use to get an inverted image that's common for astronomical telescopes.

I'm trying to understand the basis for this claim.  For example binoculars used for astronomy or military use in poor light conditions have an exit pupil diameter of about 7mm.  The 7x50 military binoculars or the Orion 9x63 are in this "Night" category.  Binoculars with smaller diameter exit pupil diameters are for "daytime" use.

This Day or Night telescope has an objective diameter of 39mm but the magnification is not specified for either day or night use, so the exit pupil is unknown.

Specifications

Based on measurements of the telescope.
Distance between Objective and eyepiece field stop (30.7") / distance between field stop and eyepiece lens (3.9") = magnification (8X).
Exit pupil = Objective diameter (1.54"; 39mm) / magnification (8) = 5mm - a common daytime exit pupil size.

Officer of the Watch

This is the designation of a newer hand held telescope also used on ships. Very common  in the UK.
These are always used as a "day" telescope, i.e. with the image erector installed.

Photos

Fig 1 Engraving
Overall
Day or Night Single Draw Telescope
Label
First Line: Barry Minories, London
Second Line: Day or Night
Day or Night Single Draw Telescope

Fig 2 Components
Day or Night Single Draw Telescope
Fig 3 Draw Tube Objective end to left
Day or Night Single Draw Telescope		 Fig 4 Draw Tube Objective end to right
Day or Night Single Draw Telescope
Fig 5 Objective
Day or Night Single Draw Telescope		 Fig 6 Huygens Eyepiece
Day or Night Single Draw Telescope

Drawing

Note:  I'm showing all the lenses as green rectangles since I don't have a way to measure their optical properties.
I can not find my Geneva Lens Clock.  If you have lens specs let me know.

2024 July 6  - Rough drawing DNTelescope.jpg
2024 July 8 - Kroil opened Erector Assy.
 DNTelescope2.jpg

Patents

TBD

Related

Alidades
Electro Optical Gadgets - includes IR pulse sender and receiver
Exotech 100BX Radiometer -  multi-spectral filters on four channels
Hilger & Watts Spectrometer D 186.3/290 - used for early physics discoveries.
Leitz 115A transit (now Sokkia 7327-60) surveyors transit
NextStar60 - cleaver microcontroller telescope using DC motors and shaft encoders
Celestron 8" Reflector & Wedge Tripod mount.
Orion GoScope 80 Table Top -
Galileoscope -
Infrared
K&E hand Levels -
K&E 76 0000 Alidade - used for map making
Mk 20 Mod 4 Gun-Bomb Sight -
Navy Mk. 18 Gyro Gun Sight -
Optics - Patents
Optical Spectrum Analyzers: Monolight, Besler, Wollensak, Ocean Optics, Spectronic, Welch, DIY Web cam & DVD grating (Ref 2 to 9)
Telescope Mounts -
T. F. Randolph Level - for land leveling
Theodolites - Sokkisha/Leitz N010C, Nikon NT-2S, Wild T2, Wild T16
Pendulum Astrolabe
PVS-4 Starlight Scope -
PVS-5 Night Vision Device -
Sky Scout -
Sky Scan -
Ukiah Lattitude Observatory
Ultraviolet
US Navy Infrared Signaling Telescope US/C-3 - W.W.II near IR sensor
VVS-2(V)4 Driver's Night Vision Viewer - advanced low light and near IR viewer.
Warren-Knight Pilot Balloon Theodolite - Got these because they can view high elevation angles because of the Nasmyth (Wiki) design the eyepiece is always horizontal.
Weston Model 594 Photronic Cell, Weston 603, 614, 615, 617, 650, 703, 715, 756, 819 & others - about visible light, but a little near IR

References

Ref 1. The Telescope Collector - Gilbert "day or night" -  Nick tells me the design is a microscope looking at the objective image.
Ref 2. The Telescope Collector - Officer of the Watch telescopes -
Ref 3. The manufacture of high-precision brass telescope tubes 1780 to 1990, 44:25 - a rectangular brass sheet is cut from a roll.  Formed into a tube, the seam soldered, then drawn using a mandrel and core rod in a press.
Ref 4.Vintage telescope masterclass - Hand-held telescopes (Part 1), 12:49 - 1750 single draw "day or Night" guillotine eyepiece protector, single element objective lens stopped way down to improve chromatic aberration, Main tube is made of wood, not brass,
Ref 5. Vintage telescope masterclass - Hand-held telescopes (Part 2), 9:07 - @1:45 "day or night"
Ref 6. Vintage telescope masterclass - Hand held telescopes (Part 3), 14:29 - @4:19 Officer of the Watch telescope

Links

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Page Created 2024 July 4