A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Stephen N.G. Davies
Date: 2019 Apr 9, 18:28 +0800
Since we are talking sextants, I have recently been approached to deliver (a very amateur) judgment on two sextants, sitting around in a cupboard, that have really posed some problems.
I am uncertain how one attaches images and so forth (no doubt Frank will promptly put me right) but in essence here it is in words.
- LORIEUX, LEPETIT, NO. 7697 (name and number on lower (brass) part of arc
• Brass ladder frame, japanned black with horizon half mirror (silvering in bad condition) with three shades
• Star telescope, standard sighting tube and inverting sun scope and provision for 3 (missing) filters
• One universal mounting bracket to fit to the frame with a double screw clamp mechanism for fine adjustment (and designed to be left in the frame when the sextant is in its box)
• Brass and inset silver (or steel) scale graduated -5 - +155 with no rack, the index arm lock being a simple screw clamp
• Index arm with intact index mirror (silvering OK but damaged around the edges) with four shades and double ended screw Vernier with hinged Vernier magnifier and simple clamp acting on reverse side of arc
• Square socket adjustment key for mirrors
• Two identical, L-shaped, brass, black painted objects with sharp, beveled edges on the short leg, stowed in fitted socket on side of box base of unknown purpose
• Shaped Bakelite handle, with interior with two supports for a cylindrical object all held behind a pivoting, thin aluminium plate closure and at the base a brass fitting with single c.2mm internal diameter tube exiting interior, on top forward corner (side away from user) a threaded recess – these last two elements possibly for some sort of sight time recorder (clockwork? pneumatic?)
• Box lid and base cracked no key, two hook fasteners and folding, bent rod copper handle. No outside markings:
o Box lid with inside a maker’s label and a label with simple maintenance instructions – no certificate attesting to accuracy or errors; two wooden arms with brown, felt pads to hold sextant in place, three, unprotected wooden fitting to hold filters and tools in place; one stowage with simple wooden turnbuckle lock against front edge of lid for a trapezoidal shaped, long object (the universal mounting bracket does not fit), which may possibly be related to the missing fitting from the inside of the handle
o box base fitted for sextant and accessories, sextant fitted in shaped, two-L-shaped, sided aluminium (curvy upper bit bent and welded (?) to lower bit) location but with no securing fittings
The maker’s label reads:
- Berthélémy, Lorieux, P. Ponthus,
Établissements Albert Lepetit (A&M)
Société à Responsibilité Limitée Capital 6.480.000
and places them at 20 rue Marie Debos, Montrouge (Seine), tel ALÉSIA 26-37 & 38
Which is an address no source seems to have for the company in many of its many guises (there is a descendent outfit still trading) and, indeed, with a name mix no source has either. My tentative dating is 1920s and I wondered, given the rather sexy handle, whether it might not have been designed for use in an aircraft.
- Sextant B: NITTO No. 2058
• Grey painted, brass A-frame based possibly on a pre-WW2 British Heath & Co. ‘Bell frame’ model, though in this case without the bell outcurves at each scale end with horizon half mirror (silvering in fair condition) and three shades (good condition). It also repeats (again without the bell ends to the outer arms) the Heath & Co ‘Bell frame’ shape of a 1938 Tamaya.
• Index arm, marked with Nitto (convex and concave lens together logo reminiscent of pre-WW2 Carl Zeiss logo) and serial number as above with index mirror (silvering fairly good) and four shades (all good) ending in a quick release drum micrometer mounted on the end of the arm with 4 screws similarly to contemporary Tamaya models (themselves copies of a pre-WW C. Plath model)
• Brass scale graduated -70 - +1370 with bottom of arc rack
• 2.5 x (?) star telescope, inverting sun scope, three telescope filters – provision for 4 filters (one missing): two ‘push-on’ for the star scope, two screw on for the inverting sun scope (one missing)
• Adjustment tool and possible oil bottle stowage;
• Shaped, brown varnished wood handle with fittings on the outside possibly for a time recording mechanism;
• Simple lockable box (no key) in good condition but brass key plate missing one screw, with fastening hooks on outer sides of side with lock; folding cast brass handle no outside markings
o interior of lower box fitted for sextant and accessories using simple wooden turnbuckle locks; one large, long trapezoidal shaped accessory location, with wooden turnbuckle lock beneath the filter stowages is missing its accessory (whatever it was, possibly related to the missing fitting on handle)
o box lid with two wooden holders, one missing its felt pad to secure the sextant in the box and some pieces of wood to secure the filters
The box has no markings on the outside and the inside of the lid also appears both bare and as if nothing has ever been attached to it. There is no certificate (Inspection Certificate/Certificate of Accuracy/Collimation Certificate/Certificate of Examination) either from the maker or from subsequent repair/adjustment by an instrument repairer.
The puzzle here is that no one seems ever to have heard of a sextant manufacturing company called Nitto. My hunch is that it is Nittoh Kogaku Kikai Seisakujyo. This was originally established in the silk weaving business as Toueisha in 1876, but in some unclear sense was refounded as Nittoh Kogaku Kikai Seisakujyo in 1943, aligned with Nihon Kogaku (Nippon Kogaku KK, later Nikon) and started manufacturing optical equipment probably under direction of the Japanese war economy. The company is also Romanized as Nittō Kōgaku K.K. (日東光学株式会社). My surmise is that Nitto produced lower quality sextants in the post-war era based on a pre-war British Heath or (less probably) Tamaya. This may have possibly been either Nihon in rivalry to Tamaya, or maybe sub-contracting to Tamaya - as we know companies called Tamaya, Ginza, Tamaya Osaka, Simex and MAC did for the well known Tamaya 633 sextant that used the Plath type ladder frame in the 1960s.
If anyone can cast any further light, especially on the fascinating handle of the Lorieux, Lepetit sextant or the identity of Nitto, I shall be most grateful.
Hon Professor, Department of Real Estate and Construction,
Hon Institute Fellow, Hong Kong Institute for the Humanities & Social Sciences,
Hon. Editor, Journal of the Royal Asiatic Society Hong Kong
c/o Department of Real Estate and Construction,
EH 103, Eliot Hall
University of Hong Kong,
Tel: (+852) 2219 4089
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