Nautical instruments
This part of the collection includes mainly navigational instruments from the early sailing period, the time when ships were made of wood and men were made of steel.
Early chart divider of brass with iron tips in fine condition with irreducible engravings.
Catalog: NM.5-21
Date: 17th century
L: 7 cm
Signed: not signed
Origin: unknown
Condition: perfect for its age, in working condition, wear consistent with age and use
Remarkable navigational protractor with cross piece in a green baize lined mahogany case. With a 0-360 degree scale and four 0-90 degree scales in the quarters. Diameter 30.6 cm.
Made by Chas. Smith, London and used by the War Department.
Catalog: NM.5-19
Date: 1900-1920
D: 30.5 cm (1 foot)
Case:
Signed: C.S © Ltd. And B.033 – W10?VC/1320
Origin: England
Condition: perfect
Artificial or mercury roof horizon, rectangular black-lacquered cast iron trough with pouring hole and brass-framed roof-shaped cover with clear glass panels. Round iron bottle filled with mercury with stopper and iron funnel, in fitted wooden carrying box, signed and made by H. Hughes & Son, London. With certificate of Examination from april 1895.
The artificial horizon is used to establish the elevation of the sun or a star when the horizon is not visible. The vertical angle between the celestial body and its reflection in the mercury was mesured. This has to be halved to establish the angle of elevation above the horizon.
Catalog: NM.5-17
Date: ca. 1850
HWL case: 13.5×19.5×15.5 cm
Label: H. Hughes & Son, Opticians, 59 Fen Church Street, London
Roof: same as on the label, No. 601, patent 95 and the name of the owner (?) V. Poole
Origin: England
Condition: perfect
Mercury is poisonous, please pay attention!
Station pointer or position finder in pine box with manual. The box contains three extra manuals and a letter addressed to Captain Croskery. All this together suggests that this is the instrument of Croskery itself.
It is not yet entirely clear whether Croskery invented the station pointer for coastal navigation, but all the compliments from colleagues and institutions on the paper at the bottom of the box suggests that.
The station pointer consists of a graduated circle and three arms. Strings have been placed in the arms for an accurate reading. The circle of this instrument has a diameter of 24 centimeters and is made of brass. The scale is divided into points and half point. Bearings can be taken directly with this instrument and transferred to the chart.
Some parts are missing from this instrument.
Compare NAV 0636 with parts of Maritime Museum Greenwich.
Catalog: NM.5-16
Date: 1892
HWL case: cm3x40x26 cm
D instrument: 24 cm
Signed: Croskery’s Patent Position Finder, reg nr 15261
Origin: England
Condition: in good and working condition, parts missing
Artificial or mercury roof horizon, rectangular black-lacquered cast iron trough with pouring hole and brass-framed roof-shaped cover with clear glass panels. Round iron bottle filled with mercury with stopper and iron funnel, in fitted wooden carrying box, signed and made by Sewill, maker tot he Royal Navy, Liverpool. Only a few copies of Sewill are known. Even the Maritime Museum in Greenwich does not have a copy.
The artificial horizon was used to establish the elevation of the sun or a star when the horizon was not visible. The vertical angle between the celestial body and its reflection in the mercury was mesured. This had to be halved to establish the angle of elevation above the horizon.
Catalog: NM.5-15
Date: ca. 1850
HWL case: 15x22x15 cm
Signed: Sewill, Maker tot he Royal Navy, Liverpool
Origin: England
Condition: excellent, perfect, the strap is broken and incomplete
Mercury is poisonous, please pay attention!
Very rare nautical slide rule made of plywood by A. M. Gordon, Glasgow, Scotland. With ‘scales of power & speed for proposed vessels on measured mile trials’ and ‘scale of IHP constant’ on the other side.
Catalog: NM.5-12
Date: ca. 1910
HWL: 0,5x34x9,5 cm
Signed: A.M. Gordon, M.I.N.A. Baltic Chambers, Glasgow
Origin: Scotland
Condition: perfect
Nice quality single draw telescope with two bras tubes, sunshade and good optics. Eye and objective lensos with a protective shutter. The mainbody is clad with leather and has taken on a nice antique patina, polished over the years. Both lenses have a sliding lens protector. The window displays flags and pendants of the British Navy. Some signs of age and use.
The stand is new made of old oak of about the same age as the telescope.
Price of the stand is E 85,=
Catalog: NM.5-10
Date: ca. 1880
L with sunshade: 58 cm, extended 96 cm (resp. 23 and 38 in)
D objective side: 40 mm (1.5 in)
Signed: not signed
Origin: England
Condition: for its age, perfect; in working condition, wear consistent with age and use
A very fine brass clinometer in original mahogany case. Clinometers have a variety of uses. With this type of clinometer the angle of inclination of a ship can be measured very accurately. For this purpose in still water, along the quay, a heavy weight is moved abeam with the loading equipment. The values found are used in stability calculations.
The instrument consists of a brass frame containing a highly sensitive cylindrical screw, graduated to minutes of a degree. The cylindrical screw is turned up until the spirit level indicates horizontal. Case and instrument have the same number 22991. In the case a correction table of 1942.
Catalog: NM.5-07
Date: 1941
HWL case: 82x277x200 mm
Case signed: E.R. Watts & Son, London – 22991 – 1941
Instrument signed: Clinometer Large – E.R. Watts & Son, London – 1941 – No. 22991
Origin: England
Condition: perfect
The sextant consists of two black lacquered round plates, the upper having an ivorine overlay. The handle is screwed into the bottom plate. The mirrors are between the plates. One mirror and the pinhole vane have a fixed position. The index mirror is moved by moving the index arm on the overlay. The position of the index mirror is read on the ivorine scale. The sextant is used in coastal navigation in combination with the station pointer.
The instrument is stored in a mahogany box. The lid contains instruction for use. The Paget sextant was designed around 1892 and marketed by Hughes. Number 609 is a fairly early instrument.
Catalog: NM.5-03
Date: ca. 1910
HWL case: 7×18,5×15,5 cm
D sextant: 11,5 cm
Signed: Hughes & Son, Ltd London – No. 609
Origin: England
Condition: perfect, in good and working condition, wear consistent with age and use