British Air Ministry Pattern
Of the smaller size sextants, it is the Very Best!
PRESENTED is another gem of a micro-mini tiny sextant that has full
size mirrors and shades, full size micrometer drum of a regular size sextant, but that has a radius of
arc of only 3 1/2 inches. The only thing of less performance is the low powered telescope which is minor. It is only the 3rd
one we’ve discovered in this remarkably fine condition. The brass frame is finished in midnight black wrinkle enamel which
is like new. The scale has a silver inlay that is graduated from – 10 to 120 degrees. The index arm has a quick release
trigger and vernier which reads to 1 arc minute. There are four index shades and three horizon shades. The fittings maintain
their original varnish which has a pleasing age patina. Every thing is designed to make this instrument perform like a full
size sextant.There are no maker’s mark,
but it carries the serial number 33934 on its arc and comes with the maker’s certificate of error. Both Heath and Hughes made
these instruments for the Air Ministry, and this one is slightly different from the Heath we previously sold. Both were one
of Britain’s Class “A“ sextant makers. Like the Heath, the index arm imprint reads: Royal
Crown
AM
REF No 6B/177 AIR
MINISTRY DESIGN: The Royal Crown and AM marks indicate this sextant was made for the military which accounts for
its exceptional quality. The AM stands for Air Ministry. Marine sextants of this type were used on seaplanes for taking anchor
bearings and also other calculations such as amplitudes of the sun and distance off angles when on the water.

PROVENANCE: Handed down to the son of a deceased yachtsman who served as navigator
for many years in long distance races aboard large yachts.
      Looking Inside the small well made sextant case

INSTRUMENT CONDITION: The mirrors show some age. The index mirror has some black stripes
along its three outside edges, but nothing that would interfere with taking an accurate sight. The horizon mirror has a black
vertical line where the mirror joins the clear glass. Again, there is 90% of the reflective surface remaining.

The beautiful varnished handle shows like new. The index arm is complete and in good working order. The frame and
all the machinery are in good working order and nothing is missing. It comes with its original pick to adjust the horizon
mirror and a small bottle of sextant oil. All the screws and fittings show their original varnish which has mellowed with
age.
THE CASE: The sextant comes housed in a high quality, varnished, Mahogany
square case with a spline added 3/4 of the way across its center to repair an old split. The case has a brass handle, hinges
and two rotary latches and a lock, but no key. All the varnish has mellowed with age and has a pleasing rich patina.
The round holder in the case holds a small flask of oil. The right side wood holder is for a pick which is
present and a small screwdriver which is missing.
  Showing the closed case. The arrows
point to the inlaid repair
  Large Index
mirror
Large Horizon
mirror
Air Ministry Markings & serial number
CERTIFICATE:
Of the three prior instruments of this type we’ve sold, this is the only one that had a maker’s certificate. In this
case, the non-adjustabe error is a maximum of 1  arc minute.

The Henry Hughes’ Instrument Certificate of error

All in all, a very rare and exceptionable example from one of the best known English instrument makers.

DIMENSIONS:Length
of index arm 5 3/4″
Width of frame at arc 5″
Radius of Arc 3 1/2“
Telescope fixed focus 2 X
Index error Nil
Side error Nil
Index mirror 46 x 30 mm
Horizon mirror 36 x 30 mm
Weight sextant 2 Lbs 7 oz 5 lbs 8 oz total
BRIEF HISTORY OF MAKER: The Henry Hughes name which we believe
to be the maker of this instrument was founded in 1838 in London as a maker of chronographic
and scientific instruments. The firm was incorporated as Henry Hughes & Sons Ltd in 1903 and in 1923, the company produced
its first recording echo sounder. In 1935, a controlling interest in the company was acquired by S. Smith & Son Ltd resulting
in the development of marine and aircraft instruments. Following the London office’s destruction in the Blitz of 1941,
a collaboration was entered into with Kelvin, Bottomley & Baird Ltd, resulting in the establishing of Marine Instruments
Ltd. Following the formal amalgamation of Kelvin, Bottomley & Baird Ltd and Henry Hughes & Sons Ltd in 1947 to form
Kelvin & Hughes Ltd, Marine Instruments Ltd acted as regional agents in the UK for Kelvin & Hughes Ltd who were essentially
now a part of Smith’s Industries Ltd founded in 1944 as the successors of S. Smith & Son Ltd.
“HUSUN”
trademark was in use starting in the 1920s. Hughes and Heath made many sextants to the same design this being one of them.
The more recognizable are the three ring sextants one under the Heath Hezzenitth brand and the other under the Hughes, Husan
brand. Both are likely the most numerous ever produced, and can still be found
in great quantity today.