Made by Norton & Gregory in the early 20th century, this large optical square for use by surveyors is engraved on the brass drum 'NORTON & GREGORY Ld, LONDON & GLASGOW’ who were instrument makers active from the latter part of the 19th cventury and well in to the 20th century. There are also the initials W.R.M who was presumably a previous owner.
Viewing is through the pinhole viewer, and unusually for this type of instrument there is a separate brass key for adjusting the mirror angles, which unscrews when required.
There is a twist action to close all apertures when not in use, and the two drums can be dismantled for cleaning and adjusting the mirrors by simply unscrewing the retaining screw on the side and pulling the two halves apart.
In excellent condition including the mirrors, it comes with its original leather case, which is also in very good sound condition with all stitching intact.
Measuring 75mm in diameter and 28mm in depth, it is a well made instrument with a substantial feel to it, it weighs just under 400 grams in its case.

This is an increasingly rare instrument called the Paget Angle Sextant which was designed toward the end of the 19th century and originally marketed by Henry Hughes & Son.
This particular example is signed ‘THE PAGET ANGLE SEXTANT, No 26164, H. HUGHES & SON, LONDON’ on the ivorine overlay.
The sextant has a black alloy frame consisting of two circular plates with the upper having an ivorine overlay, the sight has one pinhole mounted within the frame and the instrument has an outer ivorine scale from 0° to 90°. The index arm is moved by hand and  the scale is read by a black indicating line on the ivorine part of the index arm.
Dating to the early 1900's, it's housed in a good condition mahogany case which measures 180mm x 150mm x 70mm, and the total weight is just over 1.1kgs.
In good working order with very clean mirrors, these sextants are becoming more difficult to find in such good condition and in their original box.

This late 19th century instrument is called an optical square or a right angle prism, it's purpose being to facilitate the layout of a grid pattern, by enabling one to see lines to the left or right which are 90 degrees to the line of sight being viewed through the pinhole viewer.
Engraved on the brass drum 'ELLIOTT BROS LONDON' a partnersip between Frederick Henry and Charles Alfred Elliott, formed in 1853 after the death of their father William Elliott.
In good working order and measuring 47mm in diameter by 17mm in depth, it's a well made instrument, and comes with its original silk and velvet lined outer case, emblazoned 'ELLIOTT BROS LONDON' on the silk lid lining.

Dating to the post WW1 era, this brass box sextant is signed STANLEY LONDON on the face above the silvered vernier scale.
William Ford Stanley was a mathematical instrument maker who set up in business in the 1850's, and although the name Stanley has been widely copied by makers of reproduction instruments, please rest assured that this is a genuine Stanley piece!
This particular model is designed for readings to be taken through a 2 stage sliding brass pinhole shutter which incorporates a red filter on the last stage, eliminating the need for separate filter arms, as is more commonly found.
The outer cover is of the bayonet fixing type, and serves also as a base for the top section.
Constructed of brass with a black anodised finish, it has a silvered (0 - 130 degrees) vernier scale with lacquered brass fitments and mirrors, all in good condition.
A substantial instrument in full working order, it measures 75mm diameter x 40mm closed depth and weighs 560 grams in its leather case, which has had some past repairs but is still sound.

Made by William Ford Stanley, this pocket drum sextant dates from the post WW1 period and is engraved 'STANLEY LONDON' on the faceplate. It comes complete with a separate two part extending telescopic sight, incorporating a removable screw on sun filter, and two further retractable filters within the sextant drum itself.
Constructed of brass with a lacquered black finish and brass fitments, it's in excellent condition all round, with very little loss of finish.
The outer cover is of the screw on type, which serves also as a base for the top section and inside the cover there is a paper inlay, on which is printed a table of natural tangents.
The brass fitments and silvered dial (scale 0 - 140 degrees) are all in good condition, as are the lens, mirrors and filters.
In full working order it can be used with or without the telescope, as it also has the sliding brass pinhole shutter.
Weighing just over 700 grams in its case, it measures 80mm diameter by 45mm closed depth, and comes with its original fitted leather case and matching shoulder strap.
A genuine Stanley instrument, not to be confused with replicas on other sites!

Although Thomas Cooke and his two sons became partners in 1856, the name T. Cooke & Sons Ltd was not adopted until 1897. The firm was acquired by Vickers Ltd in 1916, who merged it with Troughton and Simms to form Cooke, Troughton & Simms Ltd in 1922.
This pocket drum sextant dates from that later period and is engraved 'Cooke Troughton & Simms Ltd, London & York'. It comes complete with a separate two part extending telescopic sight, incorporating a removable screw on sun filter, and two further retractable filters within the sextant drum itself.
Constructed of brass with a lacquered black finish and brass fitments, it's in very good condition all round, with only some minor lacquer loss in places.
The outer cover is of the bayonet fixing type, which serves also as a base for the top section and inside the cover there is a paper inlay, on which is printed an angle of dip table.
The brass fitments and silvered dial (scale 0 - 150 degrees) are all in good condition, as are the lens, mirrors and filters.
In full working order it can be used with or without the telescope, as it also has the sliding brass pinhole shutter.
Weighing just over 500 grams, it measures 80mm diameter by 45mm closed depth, and comes with a modern velvet drawstring pouch for added protection.

This is an increasingly rare instrument called the Paget Angle Sextant which was designed toward the end of the 19th century and originally marketed by Henry Hughes & Son.
This particular example is signed ‘THE PAGET ANGLE SEXTANT, No 651, T. COOKE & SONS Ltd, LONDON & YORK.’ on the ivorine overlay.
The sextant has an alloy frame consisting of two circular plates with the upper having an ivorine overlay, the sight has one pinhole mounted within the frame and the instrument has an outer ivorine scale from 0° to 90°.
The index arm is moved by hand, and the index/horizon glass is calibrated by capstan screws which are adjusted by means of a separate adjusting pin contained within the wooden handle.
The scale is read by a black indicating line on the ivorine part of the index arm.
Dating to the early 1900's, it is housed in a mahogany case and inside the lid written in pen, is "M.J.C. Mardel R.N.S.A (1965) - 1971", a former owner who was a member of the Royal Naval Sailing Association.
In good cosmetic condition, with some minor paint loss on the alloy frame, it's in good working order with clean mirrors, and with the case measuring 178mm x 155mm x 59 mm, the total weight is just under 1.4kgs.

Signed 'J.H.STEWARD Ltd, LONDON 3400 /|\', this is a fine WW1 era pocket box sextant issued into military service.
J H Steward was founded in 1852 by James Henry Steward, based out of The Strand, London and was a prolific maker of scientific and navigational instruments for over 100 years.
The sextant comes complete with a separate two part extending telescopic sight, incorporating a removable screw on sun filter, and two further retractable filters within the sextant drum itself.
Constructed of brass with only minor paint loss on the black finish, it's in very good condition all round with exception of a long tail on the broad arrow, where it appears the engraver may have got a bit carried away! See photos.
The brass fitments and silvered dial (scale 0 - 120 degrees) are all in good condition, as are the lens, mirrors and filters.
In full working order and weighing just over 500 grams, it measures 75mm diameter by 40mm closed depth, and comes with a modern velvet drawstring pouch for added protection.

An excellent example of an early 20th century pocket or box sextant, signed on the face 'Newman & Guardia Ltd, London.W, no 4830, 1918 /|\'.
Dated 1918, it's marked with the war department broad arrow indicating it was issued into military service.
Constructed of solid brass with original black anodised finish, the outer cover is of the bayonet fixing type and has the same makers marks engraved on the outside. Inside the cover is a paper inlay, displaying a table of natural tangents fitted inside(see photo).
The lacquered brass fitments and silvered dial (scale 0 - 130 degrees) are all in very good condition, as are the lens, mirrors and coloured filters.
In full working order, it measures 70mm diameter x 35mm closed depth, and comes with leather case impressed "D Mason & Sons Ltd. Birmingham 1918" which is also in good sound condition.

A fine example of a WW1 military pocket or box sextant in excellent condition, and signed on the face 'EXCELSIOR WORKS Co. No 1415. 1915'. It's also engraved with a military double crowsfoot on the outer cover, indicating it was formally decommissioned into the army surplus market after the war.
Constructed of oxidised lacquered brass, the outer cover is of the bayonet fixing type and has the same makers marks and serial numbers engraved on the outside.
Viewing is through a sliding brass pinhole shutter viewfinder and it has two internally housed retractable sun filters. The silvered vernier scale of 0 to 130 degrees and magnifyer lens are all in good condition, as are the mirrors.
In full working order, it measures 70mm diameter x 35mm closed depth and weighs 370 grams in its leather case, which is also in excellent condition.

Dating to the post WW1 era, this brass box sextant is unsigned on the face but has the Francis Barker Trademark London triangular logo, with the intertwined FBS letters stamped on the outside of the outer cover.
This particular model is designed for readings to be taken through a 2 stage sliding brass pinhole shutter which incorporates a red filter on the last stage, eliminating the need for separate filter arms, as is more commonly found.
The outer cover is of the screw threaded type, and serves also as a base for the top section, inside the cover there is a paper inlay on which is printed a table of natural tangents.
Constructed of brass with a black anodised finish, the silvered (0 - 130 degrees) vernier scale is in excellent condition, with all markings present and readable.
In full working order, and good overall cosmetic condition, the lacquered brass fitments and mirrors are also in good order.
It measures 75mm diameter and 40mm in closed depth, and weighs just under 550 grams in its original stitched leather case, which has the name MUNRO Architects & Surveyors of Inverness written in ink, I believe the company is still in business today.

A fine example of a WW2 military pocket or box sextant, made by Francis Barker for T A Reynolds Son & Wardale, signed on the face 'T.A.R.S. & W. Ltd, B 876', it's also engraved with the War department military arrow.
Constructed of brass with the original black finish, the outer cover is of the bayonet fixing type and has a paper inlay displaying a table of natural tangents.
The brass fitments and silvered dial (scale 0 - 140 degrees) are all in good condition, as are the mirrors and two retractable filters, and it has a sliding brass pinhole shutter viewfinder.
In full working order, it measures 68mm diameter x 39mm overall closed depth and weighs 460 grams in its leather case, which is also stamped with a military arrow.

Dating from the latter part of the 19th century, this brass pocket sextant was made by William Ford Stanley and signed 'Stanley, Gt Turnstile Holborn, London', on the face above the silvered vernier scale.
It comes complete with a separate two part extending telescopic sight, all housed in a leather case (repaired strap).
Constructed of brass with a black finish on the face and lacquered brass fitments, it's in very good condition all round.
Although the small removable screw on sun filter for the telescope is no longer present, it doesn't affect the functionality. The lenses and mirrors are all in good order and the sextant can be used with or without the telescope, as it also has the sliding brass pinhole shutter.
Measuring 75mm dia x 40mm closed depth, it weighs just over 600 grams with its case.

Made by J H Steward, this is a pre-WW1 drum clinometer probably used by artillery units in the British Army as an aid for targeting heavy guns.
It measures 70mm in diameter and is quite an ingenious device, simply turn it on its side, peer through the pinhole viewfinder, depress the button and the scale inside swings according to the angle that is being viewed, releasing the button locks the reading taken.
The clinometer is engraved 'J.H. STEWARD, LONDON' and is in really good condition with very little loss of its bronze finish.
It comes with its leather case which although worn is still sound and all stitching is intact.
A rare instrument in good working order.

Dating to around the mid 19th century, this brass pocket sextant is engraved 'J. B. Dancer Manchester - P.L.G.B.' either side of the scale.
Son of Josiah Dancer, also an optician, John Benjamin Dancer was a pioneer inventor and instrument maker who operated out of 43 Cross Street, Manchester between 1847 until his death in 1887. His trade card included the statement 'By appointment to Her Majesty's Commissioners. Prize Medal 1862'.
Although the sextant has lost some of its brass lacquer in places, it is in good undamaged condition with a screw on outer cover.
The main body features a pinhole viewfinder (with sliding brass shutter) with the lenses, mirrors and coloured filters all being in good working order, and despite some tarnishing the silvered vernier scale (range 0 - 150 degrees) is still fully legible.
Measuring 70mm diameter and 40mm overall depth, it weighs just over 500 grams and comes in a modern drawstring pouch for protection when not in use.

Dating from the latter part of the 19th century, this is a brass pocket sextant made by Troughton Simms and signed 'Troughton & Simms, London', on the face above the silvered vernier scale.
It comes complete with a separate two part extending telescopic sight, incorporating a removable screw on sun filter, and two further retractable filters within the sextant drum itself, all housed in a leather case (repaired strap) impressed WCEW on one side.
Constructed of brass with a black finish and lacquered brass fitments, it's in very good condition all round, with hardly any paint loss on the outer drum cover, although there is a small dent on one edge of the the sextant body and drum, see photos.
The lenses, mirrors and filters are all in good order, and the sextant can be used with or without the telescope, as it also has the sliding brass pinhole shutter.
In full working order, it measures 75mm dia x 45mm closed depth and weighs just over 550 grams with its case.

Dating from the early part of the 20th century, this is a brass pocket or box sextant which although unsigned was probably made by one of the major makers of the day.
Comes complete with a separate two part extending telescopic sight, incorporating a removable screw on sun filter, and two further retractable filters within the sextant drum itself, all housed in a fitted leather case.
Constructed of brass with a black finish and lacquered brass fitments, it's in very good condition all round, with some minor paint loss on the outer drum cover, and the lenses, mirrors and filters are all in good order, as is the leather case.
Both the sextant and leather case have the letters R.E.M. which I presume to be a previous owner. Can be used with or without the telescope, as it also has the sliding brass pinhole shutter, this is as complete an example as one could hope to find.
Not to be confused with replicas on other sites!

A fine example of a Troughton & Simms WW1 military pocket or box sextant in excellent condition, and signed on the face 'TROUGHTON & SIMMS, LONDON, No 2641, B 788, 1916', it's also engraved with the War department military arrow.
Interestingly, the original serial number 2641 has been officially crossed out and a new number B 788 added, the B prefix suggests the sextant was probably recalibrated by Francis Barker at a later date.
Constructed of brass with the original black anodise finish, the outer cover is of the bayonet fixing type and has the same makers marks and serial numbers engraved on the outside, inside the cover is a paper inlay displaying a table of natural tangents.
The brass fitments and silvered dial (scale 0 - 140 degrees) are all in good condition, as are the lens, mirrors and retractable filters.
In full working order, it measures 70mm diameter x 40mm closed depth and weighs 440 grams in its leather case, which is also in good sound condition.

Dating from the early part of the 20th century, this is a brass pocket or box sextant made by W F Stanley and signed 'Stanley London', on the face above the silvered vernier scale.
Comes complete with a separate two part extending telescopic sight, incorporating a removable screw on sun filter, and two further retractable filters within the sextant drum itself, all housed in a fitted leather case.
Constructed of brass with a black finish and lacquered brass fitments, it's in very good condition all round, with some paint loss on the outer drum cover, but the lenses, mirrors and filters are all in good order, as is the leather case.
Can be used with or without the telescope, as it also has the sliding brass pinhole shutter, this is as complete an example as one could hope to find.
Not to be confused with replicas on other sites!
In full working order, it measures 75mm dia x 45mm closed depth, and weighs just over 0.7kg with its case.

A fine example of a pre WW1 pocket sextant, engraved 'Supplied by Broadhurst Clarkson & Co, 63 Farringdon Road, London E.C.' on the outer cover, which is of tthe screw threaded type.

Constructed of brass with a black finish and lacquered brass fitments, it's in very good condition all round, with some paint loss. The lenses, mirrors and filters all being in good order, as is the silvered vernier scale (range 0 - 130 degrees).

Viewing is through the sliding brass pinhole shutter, but this particular model also has the threaded aperture, so can take the extending telescope sights that were often supplied as an optional extra. (not included).

In full working order, it measures 80mm diameter x 45mm closed depth, and comes with a leather case which is also in good condition, although the short tongue strap has lost its end so no longer reaches the buckle strap.

This is a WW2 MK VI field clinometer made by Stanley London, with the serial number 41520 and dated 1940.
Used by artllery regiments for measuring & setting the elevation of heavy gun barrels, it is a precision instrument which appears to be in working order, and good cosmetic condition, with only some paint loss of the black japanned finish where it was presumably clamped to a gun.
Also known as a gunner's quadrant in the USA, it measures 6.5" x 5.5" and comes in its original mahogany case which measures 7.5" x 6.5" and is also in good sound condition.
A substantial instrument, it weighs 2.5 kgs packed, so unfortunately overseas shipping is not cheap!

This WW1 military pocket or box sextant is signed on the face 'Heath & Co Ltd, 1915, No 2364', and also engraved with the War department military arrow.
Constructed of solid brass with original black anodise finish, the outer cover is of the bayonet fixing type and has the same makers marks engraved on the outside. Inside the cover is a paper inlay, displaying a table of natural tangents fitted inside.
The anodised brass fitments and silvered dial (scale 0 - 130 degrees) are all in very good condition, as are the lens, mirrors and filters.
In full working order, it measures 80mm diameter x 45mm closed depth, and comes with a leather case which is also in good condition.

This 19th century instrument is called an optical square or a right angle prism, it's purpose being to facilitate the layout of a grid pattern, by enabling one to see lines to the left or right which are 90 degrees to the line of sight being viewed through the pinhole viewer.
Dating to circa 1860, it's engraved on the brass drum 'STANLEY LONDON' who was William Ford Stanley, a mathematical instrument maker who set up in business in the 1850's.
Although the name Stanley has been widely copied by makers of reproduction instruments, please rest assured that this is a genuine Stanley piece!
In very good condition including the mirrors, it comes with its original silk and velvet lined outer case, emblazoned 'STANLEY Gt. TURNSTILE HOLBORN' on the silk lid lining.The case is also in sound condition including the release button which fastens the lid.
In good working order and measuring 50mm in diameter and 17mm in depth, it is a well made instrument, with a substantial feel to it.
The fishskin covered outer case is also in sound condition including the release button which fastens the lid, and measures 65mm diameter by 25mm deep.

A late 19th century, brass box sextant, signed on the face 'G. A. BOETTGER, CAPETOWN, MADE IN ENGLAND'
Boettger became sole agents for Siemens Brothers in South Africa from 1880 and its likely this instrument was supplied by Siemens for onward retail, which in this case appears to have been local government as it'sengraved 'Public Works Dept' on the base.
Constructed of solid brass with a black anodised finish that is still mostly intact, the silvered vernier scale is also in excellent condition, with all markings present and readable.
The outer cover is of the screw threaded type, and serves also as a base for the top section. Inside the cover there is a paper inlay, on which is printed a table of natural tangents.
The lacquered brass fitments and silvered dial (scale 0 - 140 degrees) are all in very good condition, as are the lens, mirrors and coloured filters.
In full working order, it measures 70mm diameter x 35mm closed depth, and there is no leather case.

This is a unique set consisting of a box or drum sextant with a separate cased artificial horizon, housed in the same purpose made leather case.
Made by Troughton & Simms in London, it belonged to the British Equestrian Olympian Herbert Stewart Lauriston Scott, who competed at the 1912 Stockholm Olympics, coming a very credible fourth in the individual jumping event.
He had a distinguished and versatile career, becoming a Captain in the Cavalry regiment the 4th Hussars, the same regiment that Winston Churchill had served in.
While serving in France during WW1, he also gained his Aviators certificate (no 1254) at the British Flying School at Le Crotoy, France in 1915.
He went on to become a Major in the 4th Hussars after they were re-titled the 4th Queens Own Hussars in 1921. He was born in 1885 and died in 1966.
The box sextant comes complete with a separate two part extending telescopic sight, incorporating a removable screw on sun filter, and is housed inside the sextant body for transit, which also contains two further retractable filters on levers.
The artificial horizon is contained in its own silk & velvet lined red moroccan leather covered case, and also has a separate glass vial which I believe is the original spirit level, although the liquid is no longer present as there is a small hole at one end of the glass. (shown in photos).
Both the sextant and artificial horizon are engraved ‘Troughton & Simms, London’ and the sextant cover is also engraved ‘H.S.L. SCOTT, 4th HUSSARS’.
I have never come across a set like this, and suspect it was made specially to order, I doubt you will ever see another like it, and certainly not with such provenance.
In good working order with the exception of the glass spirit level which I’m sure could be refilled and sealed, the cosmetic condition is also exceptional.

A late 19th century, brass box sextant, signed on the face 'Elliott Brothers London', and dated 1892.
Constructed of solid brass with a black anodised finish that is still mostly intact, the silvered vernier scale is also in excellent condition, with all markings present and readable.
The outer cover is of the bayonet fixing type with a brass carry handle, and serves also as a base for the top section. Inside the cover there is a paper inlay, on which is printed a table of natural tangents, along side the Elliott Bros name.
The lacquered brass fitments and silvered dial (scale 0 - 150 degrees) are all in very good condition, as are the lens, mirrors and coloured filters.
There is a War Department arrow with the letters WD 36 on both the underside & cover of the sextant, and is also impressed on the leather case. This could be a war department serial number or perhaps the year (1936?) that it was acquired for military use.
In full working order, it measures 70mm diameter x 35mm closed depth, and comes with its leather case which is also in good sound condition, and has the initials F. W. B.

An excellent example of an early 20th century pocket or box sextant, signed on the face 'Newman & Guardia Ltd, London.W, no 4531, 1918'.
Dated 1918, the design is identical to those used by the British Army in WW1, but this does not have the war department military arrow, so may have been a private purchase.
Constructed of solid brass with original black anodised finish, the outer cover is of the bayonet fixing type and has the same makers marks engraved on the outside. Inside the cover is a paper inlay, displaying a table of natural tangents fitted inside.
The lacquered brass fitments and silvered dial (scale 0 - 130 degrees) are all in very good condition, as are the lens, mirrors and coloured filters.
In full working order, it measures 70mm diameter x 35mm closed depth, and comes with leather case which is also in good sound condition.

A late 19th century, brass box sextant, signed on the face 'Elliott Brothers London'. Constructed of solid brass with a black anodised finish that is all still intact, the silvered vernier scale is also in excellent condition, and all markings present and readable. This particular model is slimmer in depth than others that I have seen, and is designed for readings to be taken through a 2 stage sliding brass pinhole shutter which incorporates a red filter on the last stage, eliminating the need for separate filter arms as is more commonly found.
The outer cover has a bayonet fixing with a small brass carry handle, and this also serves as a base for the top section.
Dating to around 1885, the sextant is in full working order, and the lacquered brass fitments and mirrors are in good order. Overall in very good condition, it measures 70mm diameter and 30mm in closed depth, and comes with a stud fastening case.

This pocket or box sextant, is dated 1918 & carries the War department military arrow showing it to be Army issue during or at the end of WW1. Made by Stanley London, it's signed on the face & the cover 'Stanley, London, No 3868, 1918'.
Constructed of solid brass, still retaining all of its original black anodised finish, the outer cover is of the bayonet fixing type and has the same makers marks engraved on the outside. Inside the cover is a paper inlay, displaying a table of natural tangents.
The lacquered brass fitments and silvered dial (scale 0 - 120 degrees) are all in very good condition, as are the lens, mirrors and coloured filters.
In full working order, it measures 70mm diameter x 35mm closed depth, and comes with what is probably its original leather case, impressed 'D. Mason & Sons Ltd, Birmingham, 1918' which is also in very good condition.