Presented is an early bronze frame, platinum
arc, antique quintant with no marks to identify the maker. However, its design is clearly that of a Heath Hezzanith
instrument made by the British instrument maker, Heath, & Co., LTD,
New Eltham, London. In this case, it is one of the earliest Hezzanith’s made. We say this with certainty
because there are no teeth on the bottom of the arc and because the screw adjustment at the bottom of the index arm drives
a worm gear and not an endless tangent screw. Consequently we date it as pre 1900 making it perhaps one of the first of the
Hezzenith line with its distinctive Bell shaped frame.
The instrument apparently found its way to the United States
during WW II as evidenced by the inspection certificate issued by the U.S. Naval Observatory on August 9, 1945 showing the
maker as Dobbie McInnis of England. The
English firm was a maker of gages to measure the efficiency of steam engines, and also is known to have sold
and made repairs to sextants. We have no explanation as to how it got to this country, but we personally know
that our Navy tested such instruments to improve our own having submitted a similar unmarked sextant to them for evaluation
in the mid 1970’s. This would account for this Heath being in near LIKE NEW and UNUSED condition, a remarkable
feat. It is almost as it would have left the factory approximately 110 years ago. The midnight black finish is original
and intact. The polished brass fittings show their original Victorian varnish.
The sextant has three
special telescopes. The two long ones display the image upside down–one of high power with cross hairs, one low power
with cross hairs, the other of low power with a wide field of view shows an erect image. This is the one fitted
which has a focus knob. All the telescopes use a common objective lens, and mount on an adjustable arm called a rising
piece that allows it to be moved towards and away from the frame. This is an advanced feature no longer found on contemporary
sextants. The only marks on it are 9416 preceded by a 9 on the left end
of the arc.
THE CASE: The sextant is housed in a 11“ 10 1/2“ x 5 1/4“ furniture
quality case with unnamed plate on its top. It has a brass campaign style handle. There are two round latch devices on
the front and a lock, but no key. Heath added an ivory pad with its name and model over the handle hardware. The
holes are present, but the tag is missing. There is a special clamp which holds the instrument securely in its chocks. There are a
few small age cracks, but nothing of significance. The interior of the case shows some revisions over the years
to accommodate different certificates, but overall the case is exceptional.
Experienced navigators understand the benefit of the
higher powered scope for obtaining longitude by the lost art of lunar distances.
Naval Observatory Certificate
SEE MORE PICTURES IN THE GALLERY BELOW
PROVENANCE: Other than for its US Naval
Observatory Inspection Certificate and that it came from a private collection of navigation instruments, its prior history
DESIGN CRITERIA: The arc measures from
– 5 to plus 155 degrees making this a quintant or one fifth of a circle. It is read by a vernier with worm gear screw
and swinging magnifier to 10 seconds of arc. The screw is encased in a protective cover. There is no quick-release
mechanism at the end of the arm for which Heath is noted. This dates this instrument as clearly being made prior to 1909,
but the worm gear dates it earlier by ten or more years. 1909 is the year the company was issued a patent for
the quick release clamp and started marking their instruments “‘HEZZANITH’ ENDLESS TANGENT SCREW AUTOMATIC CLAMP
PATENT No. 17840. Ref: G. W. Heath and
Heath & Co., “Improvements in Devices for the Adjustments of Sextants and other like Instruments,” British patent #17,840.
Heath & Co., Catalogue (London, 1921-1922), p. 506.
INSTRUMENT CONDITION: With
only a very few exceptions, it is in outstanding condition with all its metal machinery working, and shows little
to no wear.100% of its original paint and varnish remain. The right leg may have a repair. There is a small ivory plate on
the backside of the handle for making notations of the observations. The hole in it is for the case’s locking mechanism.
The horizon mirror has two small fish eye imperfections and the index mirror has some Graying at its lower extremity.
Like all vernier instruments, reading
the arc is helped by the magnifier and the gradations are sharp.The index arm clamp works freely, and the worm gear moves to
the left, but not the right which may be how it is designed. The shade glasses are complete and in good working order. The midnight
black bronze frame is in exceptional condition except for some minor evidence of age in a few places.
The instrument’s shades are clear and sharp. All three scopes are present and are clear and sharp. There is a screw
driver missing. We took some practice sights, after adjusting the index and side error to minimal error, and find
the inverted images of the two long scopes something that requires practice. The same is true of reading the vernier.
Over the years, we have sold a number of Hezzanith models, but never in this fine condition or with these special
BRIEF HISTORY OF MAKER: The Heath name was synonymous with quality from the earliest days
of the London scientific instrument trade. The Thomas Heath firm, and its predecessor’s operations date back to 1720
when Thomas Heath began making instruments on the Strand in London. Many people associated with the family firm went
on to become prominent instrument makers in their own right. Such men as Adams, Troughton, and Watkins worked there for a
time before embarking on their own. In 1845 Thomas Heath, II took the helm and the firm’s name was changed to Heath &
Co., and it continued in business until the mid 20th Century. The Heath three ring frame design Hezzanith sextant is likely
the most numerous ever produced, and can still be found in great quantity today.
All in all,
a highly desirable and exceptional example from one of better known English instrument makers.
Telescope 4 x 26 estm
Telescope 6 x 30 estm Marked “L“ Inverted image
8 x 30 estm Marked “H“ Inverted image
Length of index arm 9 3/4″
Width of frame at arc 10
Index mirror 35 x 46 mm
Horizon mirror 22 x 26 mm
Screw driver missing
Instrument weight 3
lbs 9 oz Case weight 5 lbs 8 oz Total 9 lbs 1 oz=LEFT>
one of the long scopes fitted
|STAR RATING: This fine
Collector Quality instrument rates 5 Plus STARS because it represent a rare instrument
of exceptional quality
QUALIFICATIONS: We are one of the few company’s still selling
navigation instruments that know anything about them. For purposes of judging whether Joel’s opinion counts, he
was the editor of the chapter on sextants of the 1977 Edition of “Bowditch”, The American Practical Navigator, NAVPUB 9; a
member of the U.S. Naval Academy Navigation Symposium Board, 1975 -1978; the author of a book on marine sextants, Cornell
Maritime Press,1975, and the founding president of Nautech Maritime Corporation which partnered with Tamaya of Japan in the
introduction of the MS 733 Spica, the MS 833, Jupiter, MS 933 Venus sextants and the famous NC-2 navigation computer, in the
U.S. market. Joel is a retired Master Mariner, and held a U.S. Navy “D” Qualification as a Senior Skipper – Oceans.
From 1995 until 2001, he was a Varsity Offshore Sailing Team Coach at the U.S. Naval Academy.
Some of his memberships include the: Association of Naval Aviation, Silver Wings,
The Tailhook Association, Naval Academy Sailing Squadron, McCampbell’s Aces Squadron, Naval Historical Foundation, and
the Naval Order of the United States.