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Early
19th century ebony octant with ivory scales, brass fittings, The octant is an instrument used by navigators, at sea or on land, that uses a small mirror to bring two images together--those of the sun and the horizon, for instance--to determine latitude by observing the altitude of celestial bodies. It has a fixed arc of 45°, one-eighth of a circle, mated with a scale and reflecting system that measures angles of 90° or more. John Hadley (1682-1744) described an instrument of this sort to the Royal Society of London in 1731 and obtained a British patent in 1734. Accordingly, octants are sometimes known as Hadley quadrants. This vernier octant with brass arm is absolutely complete, in very good original condition, and in full working order. The frame is solid ebony and the scales are engraved ivory. The glass elements are all intact and original. While the instrument itself is unsigned, the box bears the label of Henry Hughes, 59 Fenchurch Street, London. Henry Hughes was a second generation instrument maker of repute who began working under his own name about 1830 and moved to the Fenchurch Street address in Tower Hill about 1835. The company is still in existence today. The label denotes Hughes as a maker of "Optical, Nautical, and Mathematical" Instruments. When the frame was dismantled for cleaning, a paper label for the firm of James Gilkerson & Co., 8 Postern Row, Tower Hill was found being used as a spacer under the pivot for the arm. This could actually be the original maker of the instrument itself, Hughes acting as the seller, or from a later repair. The two addresses were within a very few hundred yards of one another; Postern Row no longer exists. Circa
1835-1845 |
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English
early 19th century universal equinoctial dial This is a portable universal sundial that can be used at most inhabited latitudes north or south of the equator. The base incorporates two level bubbles and a finely-defined compass to locate the magnetic poles. The sundial assembly itself is then rotated upward to the difference in degrees (as noted on the hinged arc at East) between the 60 degree angle of the gnomon and the user's latitude, and the time of day is read on the silvered hour circle. Conversely, one's latitude can be determined by checking the difference between a watch and the shadow thrown by the angle of the gnomon. These were much used by travelers in all parts of the world, and some are known as early as the late 17th century. This particular dial was made in London at the end of the 18th or beginning of the 19th century. The hour circle is silvered and hinged to the dial plate at North. A brass pivot attached to the hour circle supports a folding, shaped brass 60 degree gnomon. The latitude arc, hinged at East on the dial plate, is divided from 0 to 60 degrees, indicating that the instrument was largely intended for use between the equator and the far north of the British isles. The compass is of silvered brass with a highly decorated eight-point rose, and has an arm to lift and lock the needle against the glass. There are two brass bubble levels set into it. Many of these dials were supplied with wood carrying boxes, but the original does not survive. A wood display base has been made for it instead. The dial is signed simply Bradford, 136 Minories, London. This is either John or Isaac Bradford, working at that address in London between 1795 and 1822. 4.5 inches diameter dial |
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Mid-19th
century slate sundial with five gnomons by This is a most interesting
sundial, utilizing a central gnomon of 50 degrees 51 minutes
north for London, and four corresponding smaller gnomons
for a "World Time" display in the corners. The
corner dials are engraved with New York, Morning (five
hours earlier), Alexandria, Egypt,
The central gnomon has an
old repair, and one of the auxiliary gnomons is a replacement.
The slate panel is undamaged, and minimally eroded. It
is nearly all legible with a dusting of chalk. At the top (North) of the dial is a Latin inscription that is too worn to read clearly, probably having to do with time and death.
Circa 1858-1864 |
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Early 19th century mahogany "waywiser," a surveyor's measuring device. Surveyors today use a waywiser
(also known as an odometer or a perambulator) to measure
linear distances on the ground. This elegant English example
in mahogany dates from the early 19th century, and the
dial measures in yards The dial is signed by Robert Bate (1782-1847) of London, MIM and OIM, a prolific maker of instruments in the first half of the 19th century. His workshops produced globes, sundials, drafting tools, barometers, and a wide range of instruments for the Board of Excise and Customs and the Admiralty. He took two of his sons into business with him, renaming the firm Bate and Son sometime before 1840. Circa 1820-1825 |
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19th Century Irish brass sundial by Yeates & Son, Dublin This is a fine horological instrument as well as an attractive garden sundial. It is engraved with a full month-by-month equation of time table around the circumference, in addition to the hours of the day. The gnomon is set at latitude 54° 2' (54 degrees, 2 minutes), considerably north of Dublin where the dial was made. From the center, the bands of decoration & information
are: The 12 inch diameter dial plate is weathered but with every feature still very distinct, and no damage. The dial is clearly signed Made by Yeates & Son, Dublin. Samuel Yeates and Son made and signed instruments of all kinds in Dublin with this name from 1832, although Samuel himself died in 1839. The firm practiced under the same name until about WWI. Circa 1832-1850 |
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Late 19th Century English surveyor's or architect's
protractor This protractor is 6 1/8 inches in diameter, nickel-plated brass, and in immaculate condition. It is in its original mahogany velvet-lined box. The full 360 degree scale is graduated to one half of a degree. The firm of Elliott Brothers produced a wide range of instruments over many years. The founder, William Elliott, began practice in about 1795 and was joined by his sons Frederick and Charles in the 1840s. They absorbed Watkins and Hill in 1857 and advertised as Opticians to the Admiralty. Instruments signed "Elliott Brothers", as this one is, are generally 1850 and later. Elliott Brothers was still in existence in the mid-20th century. Circa 1900 |
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Large Regency period English vernier octant The name octant derives from the Latin octans meaning eighth part of a circle, referring to the angle of 45 degrees between the arms of the frame. The ivory scale is divided into 90 degrees, or one fourth of a circle. John Hadley (1682-1744) described an instrument of this sort to the Royal Society of London in 1731 and obtained a British patent in 1734. Accordingly, octants are sometimes known as Hadley quadrants. This is a fine, large mahogany-framed octant with ivory scales and a decoratively engraved 16 inch arm. The arm's engraving depicts a swan among reeds with flowers and foliage.The instrument is in immaculate original condition overall. The brass and ivory have been lightly cleaned and the frame has been cleaned and waxed. It includes a custom-made mahogany and brass display stand. This octant is signed Josh. Gaitskill, Wappin (Wapping), London. Joseph M. Gaitskill, NIM (Nautical Instrument Maker) practiced at two Wapping High Street addresses, 123 and 129, between 1793 and 1823. Wapping is just east of Tower Hill and the concentration of 18th-19th century instrument makers. Circa 1800-1820 |
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Early 18th century brass portable horizontal sundial by Delure, Paris. The plate uses a 3 5/8 inch diameter revolving round dial with Roman numerals. The compass is decorated with a four-point rose and directionals, and has the original blued steel hand. The hinged gnomon with stylized bird pointer in the manner of Butterfield is scaled 40-60 degrees. The square plate with four threaded, adjustable feet is engraved Delure, Paris. 4 5/8 in. square. The maker is either Jean-Baptiste-Nicolas Delure (worked 1695-1736) or his son Claude, apprenticed in 1723. Early 18th century |
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Aneroid barographs first appeared in 1867, and credit for the invention is given to the firm of Breguet who exhibited the first one at the Paris International Exhibition in that year. Barographs have been used to record atmospheric pressure in weather stations and l This instrument is labeled the Cyclo-Stormograph, and was sold by the Taylor Instrument Company of Rochester, New York. It was made by their Short & Mason subsidiary in England, and is in full working order. The case is mahogany with all original glass panels and original finish, and the fittings are nickel-plated steel. The clock, and its original winding key, is probably English in manufacture and uses a lever escapement. There is a repairer's mark on the clock for 1921. Charts and recording ink are included. Taylor Instrument Company started in 1851 and purchased Short & Mason in 1900. Short & Mason patented this form of barograph, with the vacuum chamber under the base plate, in 1904. In 1915, the term "Cyclo-
Circa 1915-1920 |