Measuring & Mapping

Vernier Compass

Where, how far, and how much? People have invented an astonishing array of devices to answer seemingly simple questions like these. Measuring and mapping objects in the Museum's collections include the instruments of the famous—Thomas Jefferson's thermometer and a pocket compass used by Meriwether Lewis and William Clark on their expedition across the American West. A timing device was part of the pioneering motion studies of Eadweard Muybridge in the late 1800s. Time measurement is represented in clocks from simple sundials to precise chronometers for mapping, surveying, and finding longitude. Everyday objects tell part of the story, too, from tape measures and electrical meters to more than 300 scales to measure food and drink. Maps of many kinds fill out the collections, from railroad surveys to star charts.

Place: United Kingdom

Charles Frodsham Box Chronometer

This instrument is a specialized timekeeper designed for finding longitude at sea. Its form is that of the standardized 19th-century marine chronometer. It was transferred to the Smithsonian from the U.S. Navy’s Bureau of Ships.
Description
This instrument is a specialized timekeeper designed for finding longitude at sea. Its form is that of the standardized 19th-century marine chronometer. It was transferred to the Smithsonian from the U.S. Navy’s Bureau of Ships. The chronometer’s finisher, the firm of Charles Frodsham, traded in high-quality chronometers, clocks and watches. Frodsham (1810-71), was the son of William James Frodsham, co-founder of Parkinson & Frodsham. The younger Frodsham’s firm underwent many name and address changes, but continued in business from roughly 1837 until it became a subsidiary of Devon Instruments in 1977.
Mechanism details:
Escapement: Earnshaw, spring detent
Duration: 56-hour
Power source: Spring drive with chain and fusee
Balance spring: helical, blued steel
Key missing
Bowl details:
Brass bowl, fitted with a sprung cylindrical inner bowl as a dust cover (original work)
Brass fittings for gimbal, gimbal missing
Bezel screwed and milled
Crystal flat, small unpolished chamfer
Dial details:
Engraved and silvered brass
Indicates hours, minutes, seconds, winding level up and down
Hands: blued steel, fleur-de-lys
Inscription: "CHARLES FRODSHAM / 7 Pavement Finsbury Squr, / London No.1909”
References:
1. Gould, Rupert T. The Marine Chronometer. London: Holland Press, 1960.
2. Mercer, Tony. Chronometer Makers of the World. Essex: NAG Press, 1991.
3. Mercer, R. Vaudry. The Frodshams. The Story of a Family of Chronometer Makers. London: Antiquarian Horological Society monograph 21, 1981.
4. Whitney, Marvin E. The Ship's Chronometer. Cincinnati: American Watchmakers Institute Press, 1985.
Location
Currently not on view
date made
1838-1843
1838 - 1843
maker
Charles Frodsham
ID Number
ME.314267
catalog number
314267
accession number
198140

Sextant

This sextant belonged to Haverford College, and probably dates from the second half of the 19th century. The frame is brass. The silvered scale is graduated every 15 minutes from -5° to +130° and read by vernier with tangent screw and swinging magnifier to single minutes of arc.
Description
This sextant belonged to Haverford College, and probably dates from the second half of the 19th century. The frame is brass. The silvered scale is graduated every 15 minutes from -5° to +130° and read by vernier with tangent screw and swinging magnifier to single minutes of arc. The arc is engraved "JOHN BRUCE & SON, Liverpool."
Location
Currently not on view
date made
mid 19th century
maker
John Bruce & Son
ID Number
1981.0745.07
catalog number
1981.0745.07
accession number
1981.0745

Aneroid Barometer

The inscriptions on the face of this barometer read “J. & H. J. GREEN / NEW YORK” and “JAS PITKIN / Maker / LONDON / COMPENSATED” and “U.S.G.S. No 181.” They indicate a date between 1879 and 1885 when James and Henry J. Green were working in partnership. The U.S.
Description
The inscriptions on the face of this barometer read “J. & H. J. GREEN / NEW YORK” and “JAS PITKIN / Maker / LONDON / COMPENSATED” and “U.S.G.S. No 181.” They indicate a date between 1879 and 1885 when James and Henry J. Green were working in partnership. The U.S. Geological Survey was established in 1879.
The pressure scale around the circumference of the face reads from 20 to 31 inches of mercury; the altitude scale reads from zero to 12,000 feet.
James Pitkin received a British provisional patent (#2947) for “Improvements in Aneroid Barometers” in 1861. In 1870, together with Thomas W. Short, his partner at that time, he brought out an Illustrated Catalogue of Aneroid Barometers.
Location
Currently not on view
date made
1879-1885
retailer
J. & H. J. Green
maker
Pitkin, James
ID Number
PH.247925
catalog number
247925
accession number
47736

Geodetic Transit

This 30-inch transit was made by Troughton & Simms in London for the U. S. Coast Survey, probably in the late 1840s. Only the unusually short trunnions, telescope, small vertical circle, and micrometer eyepiece remain.
Description
This 30-inch transit was made by Troughton & Simms in London for the U. S. Coast Survey, probably in the late 1840s. Only the unusually short trunnions, telescope, small vertical circle, and micrometer eyepiece remain. The standards, graduated horizontal circle, and tripod base are missing.
Ref: C. A. Schott, "Determination of the Astronomical Azimuth of a Direction," United States Coast Survey Annual Report (1866), Appendix No. 11.
Location
Currently not on view
date made
late 1840s
maker
Troughton and Simms
ID Number
PH.316510
accession number
225703
catalog number
316510

Box Sextant

A box (or pocket) sextant works like a traditional sextant, but here the mechanism is enclosed in a brass box of about 3 inches diameter.
Description
A box (or pocket) sextant works like a traditional sextant, but here the mechanism is enclosed in a brass box of about 3 inches diameter. William Jones, a leading instrument maker in London, introduced the form in 1797.
This example has a silvered scale that is graduated every 30 minutes from -5° to +145° and read by vernier to single minutes of arc. The inscription reads "H. HUGHES & SON, LTD. LONDON No 510 1918." The inscription on the leather case reads "T. J. WEEKS & SONS 1916."
Ref: William Jones, "Description of a New Pocket Box Sextant," in George Adams, Geometrical and Graphical Essays, 2nd ed. by William Jones, (London, 1797), pp. 283-285.
Location
Currently not on view
date made
early 20th century
after 1903
maker
Hughes
ID Number
PH.336361
catalog number
336361
accession number
1977.1038

Wheel Barometer

Invented in the 1660s by Robert Hooke, the "curator of experiments" in the new Royal Society of London, the “wheel” or “banjo” barometer has a tube that is bent into a J shape; a float, sitting on the shorter end of the tube, connects with a circular scale that is large and easil
Description
Invented in the 1660s by Robert Hooke, the "curator of experiments" in the new Royal Society of London, the “wheel” or “banjo” barometer has a tube that is bent into a J shape; a float, sitting on the shorter end of the tube, connects with a circular scale that is large and easily read. Barometers of this sort have long been popular for domestic use. This example is marked “D. Fagioli & Son, 39 Warner St Clerkenwell” and was made in London, perhaps in the 1840s. The dial reads from 28 to 31 inches of mercury. In addition to the barometer itself, there is a twisted gut hygrometer, a spirit thermometer, and a convex mirror. The Taylor Instrument companies gave it to the Smithsonian in 1923.
Location
Currently not on view
date made
ca 1839-1854
maker
Dominic Fagioli & Son
ID Number
PH.308173
accession number
70532
catalog number
308173

Theodolite

This is a typical English theodolite from the middle years of the nineteenth century, with an inscription that reads: Edwd Davis, Leeds."Currently not on view
Description
This is a typical English theodolite from the middle years of the nineteenth century, with an inscription that reads: Edwd Davis, Leeds."
Location
Currently not on view
date made
ca. 1850
ID Number
PH.329793
accession number
286914
286914
catalog number
329793

Ramsden Dividing Engine

Making precisely divided scales was of great importance to eighteenth and nineteenth century navigation and science. In 1775 the English instrument-maker Jesse Ramsden completed this machine, designed to divide arcs of circles automatically.
Description
Making precisely divided scales was of great importance to eighteenth and nineteenth century navigation and science. In 1775 the English instrument-maker Jesse Ramsden completed this machine, designed to divide arcs of circles automatically. The instrument has a mahogany frame with three legs and three frictionless wheels. These wheels support a heavy bronze wheel which is covered on its outer rim with a brass ring, cut with 2160 gear teeth. These teeth engage a screw on one side of the machine. Turning this screw 6 times rotates the carriage for the stylus exactly one degree. An object to be divided was clamped to the arms of the bronze wheel, with the cutting mechanism was above it.
Ramsden's invention won him an award from the British Board of Longitude. By the mid-nineteenth century, even small American instrument-makers had begun to buy dividing engines. The Philadelphia firm of Knox and Shain, which made navigational instruments, purchased Ramsden's dividing engine from his successors for their use.
Location
Currently not on view
date made
1775
maker
Jesse Ramsden
ID Number
MA.215518
catalog number
215518
accession number
40282

Solar Radiation Thermometer

In the late 18th century, scientists set out to determine the intensity of solar radiation overall, as well as the intensity of radiation in different parts of the spectrum.
Description
In the late 18th century, scientists set out to determine the intensity of solar radiation overall, as well as the intensity of radiation in different parts of the spectrum. In time they learned that the temperature of a black object was related to the intensity of the incident radiation and the movement of the ambient air. Negretti & Zambra’s solar radiation thermometer, the first commercial instrument suitable for this purpose, was unveiled in 1864. It had a blackened bulb, and was encased in a second glass tube from which the air had been evaporated. James J. Hicks obtained a British patent for a method of testing the vacuum of a solar thermometer in 1873, and described his solar radiation thermometer at a meeting of the British Meteorological Society in early 1874.
This example consists of a mercury-in-glass thermometer with a constriction in the stem just above the spherical bulb. The white enamel back of the stem is marked "202" and "J. Hicks. 8 Hatton Garn. London" and "Hicks's Patent No. 3647" and "14951" with the K/O monogram of the Kew Observatory. The clear front is graduated every degree F. from -5 to +192. This thermometer is encased in a glass jacket from which the air has been evacuated. The jacked is provided with two platinum electrodes that can be connected to a spark coil so that the vacuum can be checked, a feature described in Hicks' 1873 patent. It was made after the issuance of Hicks' patent in 1873 and before the expansion of his business to 8, 9, & 10 Hatton Garden in the 1880s.
Ref.: W. E. K. Middleton, A History of the Thermometer (Baltimore, 1966), pp. 162-164.
James J. Hicks, Illustrated and Descriptive Catalogue of Standard, Self-Recording, and Other Meteorological Instruments (London, n.d.), pp. 60-61.
Location
Currently not on view
date made
ca 1873-1885
maker
J. J. Hicks
ID Number
PH.314560
accession number
204612
catalog number
314560

Box Sextant

A box (or pocket) sextant works like a traditional sextant, but here the mechanism is enclosed in a brass box of about 3 inches diameter.
Description
A box (or pocket) sextant works like a traditional sextant, but here the mechanism is enclosed in a brass box of about 3 inches diameter. William Jones, a leading instrument maker in London, introduced the form in 1797.
This example has a silvered scale that is graduated every 30 minutes from -3° to +148° and read by vernier with swinging magnifier to single minutes of arc. The "Gilbert & Sons, London" inscription above the magnifier refers to a Navigation Warehouse in London that flourished from 1806 to 1819.
Ref: William Jones, "Description of a New Pocket Box Sextant," in George Adams, Geometrical and Graphical Essays, 2nd ed. by William Jones, (London, 1797), pp. 283-285.
Location
Currently not on view
date made
early 19th century
maker
Gilbert and Sons
ID Number
PH.318442
accession number
234476
catalog number
318442

Casella Scale of British and Pyramid Inches

This white ceramic rule is stored in a wooden case lined with red felt, surrounded by wooden shapes to hold it in place and underneath a piece of plywood. The interior of the rule has two scales.
Description
This white ceramic rule is stored in a wooden case lined with red felt, surrounded by wooden shapes to hold it in place and underneath a piece of plywood. The interior of the rule has two scales. The first is in red ink, divided to twentieths of a British inch, and numbered by ones from 0 to 25. A small scale dividing one inch into hundredths is to the left of this scale, and an extra 1/10" is at the right of the scale. The second scale is in black ink, divided to twentieths of a "pyramid inch," and numbered by ones from 0 to 25.
The scale is marked: SCALE OF BRITISH INCHES, (/) For residual error, at Temperature 68° F., see note on case. (/) SCALE OF 25 PYRAMID INCHES, OR 1 PYRAMID CUBIT. (/) at Temp. 68° F., = one ten-millionth of the earth's semi-axis of Rotation; with a Residual error, see note on case. The upper right corner of the scale is marked in red: B. & P. SCALE, No. 2. (/) May, 1867. The lower right corner of the scale is marked in black: MADE & DIVIDED BY (/) L. CASELLA. (/) 23. HATTON GARDEN, LONDON.
Two thermometers are screwed into the case on either side of the scale. The first is divided by single degrees Fahrenheit and numbered by tens from 20 to 140. The second is divided by two degrees Fahrenheit and numbered by tens from 10 to 150. Three-fourths of its tube has been missing since it arrived at the Museum in 1987. Both thermometers are marked: J. M. BRYSON (/) OPTICIAN (/) EDINBURGH. James Mackay Bryson (1824–1894), whose firm was known for making thermometers, came from a family of Edinburgh instrument makers and scientists.
A handwritten note on Royal Observatory of Edinburgh stationery is pasted inside the lid of the case. It reads, "1872 (/) The 'British Inches' of this scale, in Red divisional (/) lines, have been found by a preliminary Microscopic comp- (/) -arison to be true, for their whole 25 inch sum of (/) length, to within half the thickness of one of the division lines, (/) at the temperature of 68* Fah. The expansion for an in- (/) -crease of 1*F. on the whole 25 inches in length, = (/) = 0.00004 of an inch, nearly. (/)The above red British Inches are those in (/) terms of which the Earth has been measured in modern (/) times. The black Inches on the lower part of (/) the scale, are the Ancient Inches of the Great (/) Pyramid; in terms of which Inches, both the chief (/) measures of that Monument, and the modern (/) measures of the Earth, come out in round and (/) even numbers of fives and tens. They are, each (/) of them 0.001 of an inch longer than the British Inch. (/) P.S. (/) Ast. R. for Scotd."
Charles Piazzi Smyth (1819–1900) was Astronomer Royal of Scotland from 1846 to 1888. He did significant scientific work, including pioneering high-altitude observing and solar astronomy, but he was also obsessed with pyramidal numerology. From January to April, 1865, he and his wife, Jessica, made careful measurements of every surface of the Great Pyramid at Giza. He concluded that the pyramid was constructed using a measurement system he called "pyramid inches," which were each one ten-millionth of the earth's semi-axis of rotation. Since the pyramid inch was so close in length to the British inch, Smyth recommended that Great Britain retain the imperial system of weights and measures rather than adopt the metric system.
To visually demonstrate the agreement between the systems of measurement, Piazzi Smyth commissioned London instrument maker Louis Pascal Casella (1812–1897) to make rules like this one when Smyth published an account of his research in 1867. Since there is a discrepancy between the date on this rule and the note in the lid, the example owned by National Museums Scotland (online ID 000-190-004-745-C, catalog number T.1962.108) may be older than this instrument. By 1876 the Science Museum in London was also exhibiting a Casella scale of British and pyramid inches, donated by Piazzi Smyth. Library staff at Augustana College in Rock Island, Ill., were unable to determine how this object ended up at the college. Casella did not advertise the rule in his 1871 catalog.
References: Charles Piazzi Smyth, Life and Work at the Great Pyramid, 3 vol. (Edinburgh, 1867); L. Casella, An Illustrated Catalogue of Surveying, Philosophical, Optical, Photographic, and Standard Meteorological Instruments (London, 1871); Science and Art Department of the Committee of Council on Education, Catalogue of the Special Loan Collection of Scientific Apparatus at the South Kensington Museum, 2nd ed. (London, 1876), 42; H. A. Brück and M. T. Brück, The Peripatetic Astronomer: The Life of Charles Piazzi Smyth (Bristol, Eng.: Adam Hilger, 1988), 95–134; T. N. Clarke, A. D. Morrison-Low, and A. D. C. Simpson, Brass & Glass: Scientific Instrument Making Workshops in Scotland (Edinburgh, 1989), 112–117; National Museums Scotland, Online Collections Database, http://nms.scran.ac.uk/; "People: L. Casella," Waywiser, Harvard University Department of the History of Science, http://dssmhi1.fas.harvard.edu/emuseumdev/code/eMuseum.asp?lang=EN; accession file.
Location
Currently not on view
date made
1867–1872
maker
Casella, Louis Paschal
ID Number
1987.0196.01
accession number
1987.0196
catalog number
1987.0196.01

Orrery

This crank-operated device shows the orbital motions of Mercury, Venus, and the Earth around the Sun, and the Moon around Earth. The circular wooded base rests on three short feet, and is covered with an ornately engraved paper plate.
Description
This crank-operated device shows the orbital motions of Mercury, Venus, and the Earth around the Sun, and the Moon around Earth. The circular wooded base rests on three short feet, and is covered with an ornately engraved paper plate. One cherub on this plate holds a sign that reads “Designed for the / NEW PORTABLE / ORRERIES / by W. Jones.” Another cherub holds a sign that reads “and made and sold by / W. & S. JONES / 135 Holborn / London.” There is also “A TABLE of the principal AFFECTIONS of the / PLANETS / Jan’y 1st 1794 / Published as the Act directs by / W. & S. Jones”
William S. Disbrow, a physician in Newark, N.J., who attained fame as a collector of art, books and scientific specimens, gave this instrument to the Smithsonian in 1902.
William Jones (1763-1831) and his brother Samuel (d. 1859) made and sold mathematical, optical and philosophical instruments. They began in business at 135 Holborn in 1792, and moved to 30 Holborn in 1800.
Ref: William Jones, The Description and Use of a New Portable Orrery on a Simple Construction (London, 1784).
Henry C. King and John R. Millburn, Geared to the Stars. The Evolution of Planetariums, Orreries, and Astronomical Clocks (Toronto, 1978), pp. 207-210.
Location
Currently not on view
date made
1790s
maker
W. & S. Jones
ID Number
PH.215538
catalog number
215538
accession number
40279

Thermometer

This mercury-in-glass thermometer has a cylindrical bulb. The milk-white back is marked "L. Casella. London. 14490." The clear front is graduated every degree Fahrenheit from -25 to +130. It was made before the death of Louis Casella in 1897.Currently not on view
Description
This mercury-in-glass thermometer has a cylindrical bulb. The milk-white back is marked "L. Casella. London. 14490." The clear front is graduated every degree Fahrenheit from -25 to +130. It was made before the death of Louis Casella in 1897.
Location
Currently not on view
maker
L. P. Casella
ID Number
PH.317445
accession number
230396
catalog number
317445

Reflecting Circle

This incomplete example of an unusual type of reflecting circle came from the U.S. Naval Observatory. It may have belonged to the Navy’s Depot of Charts and Instruments, and thus date from the 1830s. The inscription reads "Dollond London."Currently not on view
Description
This incomplete example of an unusual type of reflecting circle came from the U.S. Naval Observatory. It may have belonged to the Navy’s Depot of Charts and Instruments, and thus date from the 1830s. The inscription reads "Dollond London."
Location
Currently not on view
maker
Dollond
ID Number
PH.327707
catalog number
327707
accession number
283654

Telescope (Spyglass)

The tube of this telescope consists of two threaded wooden (mahogany) sections screwed together that measure 113 cm (closed) or 117.5 cm (fully extended). The achromatic objective lens measures 3.5 cm in diameter (or 3.4 cm clear diameter).
Description
The tube of this telescope consists of two threaded wooden (mahogany) sections screwed together that measure 113 cm (closed) or 117.5 cm (fully extended). The achromatic objective lens measures 3.5 cm in diameter (or 3.4 cm clear diameter). The eyepiece consists of four lenses in a brass cylinder (5 separate brass cylinders, screwed together) with a sliding brass cover. The instrument gives gives an erect (terrestrial) image.
The "Nairne, London" inscription on the sliding brass lens cover refers to the important instrument maker, Edward Nairne (1726-1806).
Ref: D.J. Warner, "Edwarne Nairne: Scientist and Instrument Maker," Rittenhouse 12 (1998): 65-93.
Location
Currently not on view
maker
Nairne, Edward
ID Number
PH.325412
accession number
256202
catalog number
325412

Sextant

This sextant is somewhat unusual in that it has a brass frame, reinforced brass index arm, and ivory (rather than metal) scale. This scale is graduated every 20 minutes from -5° to +125° and read by vernier with tangent screw and swinging magnifier to 30 seconds of arc.
Description
This sextant is somewhat unusual in that it has a brass frame, reinforced brass index arm, and ivory (rather than metal) scale. This scale is graduated every 20 minutes from -5° to +125° and read by vernier with tangent screw and swinging magnifier to 30 seconds of arc. The "Spencer Browning & Co., London" inscription on the arc refers to a firm that was in business from 1840 to 1870.
Location
Currently not on view
date made
1840-1870
maker
Spencer, Browning & Co.
ID Number
1981.0942.01
catalog number
1981.0942.01
accession number
1981.0942

Capt. Field's Improved Hinged Parallel Rule Signed Henry Hughes & Son

This 21" German silver hinged parallel rule has two small knobs for positioning the instrument. Brass round pieces cover the screws securing the two hinges. An indentation is on both blades at the center of the rule, with a line marking the center.
Description
This 21" German silver hinged parallel rule has two small knobs for positioning the instrument. Brass round pieces cover the screws securing the two hinges. An indentation is on both blades at the center of the rule, with a line marking the center. The edges of the top blade are marked as a rectangular protractor, and the edges of the bottom blade are marked for nautical compass points.
The center of the top blade is marked: U. S. C. & G. S. NO. 331. The right end of the top blade is marked: CAPT. FIELD'S IMPD. The right end of the lower blade is marked: H. HUGHES & SON LTD. LONDON. The left end has the firm's "HUSUN" logo, with a sun above the letters and waves below the letters.
Capt. William Andrew Field (about 1796–1871) of Britain added a protractor and compass scales to hinged parallel rules in 1854. This made it easier for ship navigators to move the rule without losing track of the ship's course. Henry Hughes & Son made marine and aeronautical navigational instruments in London from 1828 to 1947 and incorporated in 1903. According to the accession file, the U.S. Coast & Geodetic Survey acquired this rule on August 21, 1919, and last issued it on September 5, 1922. Compare to MA.309662 and MA.309663.
References: "Field's Parallel Rule," The Nautical Magazine and Naval Chronicle 23, no. 5 (May 1854): 280; Peggy A. Kidwell, "American Parallel Rules: Invention on the Fringes of Industry," Rittenhouse 10, no. 39 (1996): 90–96; National Maritime Museum, "Captain Field's Improved Parallel Rule," Object ID NAV0602, http://collections.rmg.co.uk/collections/objects/42814.html; Science Museum Group, "Henry Hughes and Son Limited," Collections Online – People, http://collectionsonline.nmsi.ac.uk/detail.php?type=related&kv=58792&t=people.
Location
Currently not on view
date made
1919
ID Number
MA.309661
catalog number
309661
accession number
106954

Dip Circle

This Kew pattern dip circle dates from the early decades of the twentieth century. The inscription reads "Dover, Charlton Kent, Circle 158." A paper note in the wooden carrying case states that the U.S.
Description
This Kew pattern dip circle dates from the early decades of the twentieth century. The inscription reads "Dover, Charlton Kent, Circle 158." A paper note in the wooden carrying case states that the U.S. Navy lent it for observations during the second International Polar Year which ran from September 1932 to September 1933. The loan may have been to the Carnegie Institution of Washington which, fifty years later, donated it to the Smithsonian.
Location
Currently not on view
maker
Dover
ID Number
1983.0039.03
accession number
1983.0039
catalog number
1983.0039.03

Repeating Circle

This is one of two double repeating circles that Ferdinand Rudolph Hassler, the first superintendent of the U. S. Coast Survey, ordered from Edward Troughton in London in 1812, and that was shipped in 1815.
Description
This is one of two double repeating circles that Ferdinand Rudolph Hassler, the first superintendent of the U. S. Coast Survey, ordered from Edward Troughton in London in 1812, and that was shipped in 1815. The large circle may be angled from vertical to horizontal to the opposite vertical position. It is graduated to 10 minutes, and read by four verniers and two magnifiers to single minutes.
A repeating circle is a geodetic instrument with two telescopes that is designed to reduce errors by repeated observations taken on all parts of the circumference of a circle. The form was developed by the Chevalier de Borda, first executed by Etienne Lenoir in Paris around 1789, and popular for about 50 years.
Ref: F. R. Hassler, "Papers on Various Subjects Connected with the Survey of the Coast of the United States," Transactions of the American Philosophical Society 2 (1825): 232-420, on 315-320 and pl. VII.
"The Repeating Circle Without Reflection, as made by Troughton," in The Cyclopaedia: or, Universal Dictionary of Arts, Sciences, and Literature, edited by Abraham Rees (London, 1819), Vol. VII, Art "Circle."
Location
Currently not on view
maker
Troughton and Simms
ID Number
PH.314640
catalog number
314640
accession number
208213

John Roger Arnold Box Chronometer

This instrument, made by John Roger Arnold about 1825, is a specialized timekeeper for finding longitude at sea.
Description
This instrument, made by John Roger Arnold about 1825, is a specialized timekeeper for finding longitude at sea. The chronometer was part of the James Arthur Collection at New York University, and the university donated a portion of the collection, including the chronometer, to the Smithsonian in 1984.
To find longitude at sea, a chronometer was set to the time of a place of known longitude, like Greenwich, England. That time, carried to a remote location, could be compared to local time. Because one hour of difference in time equals 15 degrees difference in longitude, the difference in time between the chronometer and local time would yield local longitude. The instruments require careful handling to keep precise time. Although the original box for this instrument has not survived, most chronometers are fitted in a wooden box in a gimbal to remain level and compensate for the movement of a ship at sea.
John Roger Arnold (1769-1843) learned watchmaking from his father, chronometer pioneer John Arnold, and Abraham Louis Breguet. The Arnolds were in business as Arnold & Son between 1787 and 1799, when the father died. In 1805 John Roger Arnold accepted the English Board of Longitude’s posthumous award to his father for improvements to the marine chronometer, which included simplifications that permitted others to undertake batch production of chronometers—a detached escapement, a helical balance spring and a temperature-compensated balance. The younger Arnold continued the business and between 1830 and 1840 took in partner Edward John Dent. In that decade, the firm made about 600 chronometers.
Mechanism details:
Escapement: Arnold, spring detent
Duration: 8-day
Power source: Spring drive with chain and fusee
Balance spring: helical, blued steel
Balance: J. R. Arnold with built-in aux. comp. Patented in 1821 (#4531)
Inscription: "Jn. R. Arnold _ London. Invt et Fecit No 491" on backplate
Dial details:
Engraved and silvered brass
Indicates hours, minutes, seconds
Inscription: “ARNOLD. / London / No 491" on dial
Blued steel spade hands
Brass bowl; bayonet-fitted bezel; convex, plain crystal
No box
No winding key, sprung dust cover over winding work
References:
1. Gould, Rupert T. The Marine Chronometer. London: Holland Press, 1960.
2. Mercer, Tony. Chronometer Makers of the World. Essex: NAG Press, 1991.
3. Mercer, Vaudrey. John Arnold & Son, Chronometer Makers, 1762-1843. London: The Antiquarian Horological Society, 1972.
4. Mercer, Vaudrey. The Life and Letters of Edward John Dent, Chronometer Maker and some account of his Successors. London: The Antiquarian Horological Society, 1977.
5. Whitney, Marvin E. The Ship's Chronometer. Cincinnati: American Watchmakers Institute Press, 1985.
Location
Currently not on view
date made
ca 1825
maker
John Roger Arnold
ID Number
1984.0416.014
accession number
1984.0416
catalog number
1984.0416.014

Aneroid Barometer

This pocket aneroid barometer is 2 inches diameter. The inscription on the face reads: “COMPENSATED / TEMP ALT. SCALE / 50° FAHT / J. H.
Description
This pocket aneroid barometer is 2 inches diameter. The inscription on the face reads: “COMPENSATED / TEMP ALT. SCALE / 50° FAHT / J. H. STEWARD LTD / 406, STRAND / 457, WEST STRAND / LONDON / 6191.” The circumference of the face is graduated for altitude, from -10 to +1500 feet. An inner circle is graduated from 17.5 to 31 inches of mercury. A paper label in the lid of the leather case provides a correction to be applied to the altitude scale for mean air temperature above or below 50° Fahrenheit.
James Henry Steward opened an optical instrument shop at 406 Strand in 1857, a second shop at 457 West Strand in 1886, and a third shop at 7 Gracechurch St. in 1893. While Steward sold this instrument, he probably did not make it.
This was used by the Washington born intaglio artist Benson Bond Moore. The Archives of American Art transferred it to the National Museum of American History.
Location
Currently not on view
date made
late 19th century
maker
J. H. Steward. Ltd.
ID Number
1999.0007.01
catalog number
1999.0007.01
accession number
1999.0007

Theodolite

This early example of a transit theodolite was made for the U. S. Coast Survey in the 1840s.
Description
This early example of a transit theodolite was made for the U. S. Coast Survey in the 1840s. The "Thomas Jones, 4 Rupert St London" inscription refers to Thomas Jones (1775–1852), an instrument maker who worked for Jesse Ramsden, and who was elected a Fellow of the Royal Society of London in 1835.The horizontal and vertical circles are silvered, and read by verniers and magnifiers to 30 seconds.
Ref: Gloria Clifton, Directory of British Scientific Instrument Makers 1550–1851 (London, 1995), p. 154.
Location
Currently not on view
date made
1840s
maker
Jones, Thomas
ID Number
PH.314634
accession number
208213
catalog number
314634

A MAP / of / MARYLAND / with the / DELAWARE / COUNTIES / and the / Southern part of NEW JERSEY &c. / By T. Kitchin Geogr

Thomas Kitchin (1718-1784) was an English engraver and cartographer who produced many maps for the London Magazine. This one appeared in the issue for August 1757. It extends from lat.
Description
Thomas Kitchin (1718-1784) was an English engraver and cartographer who produced many maps for the London Magazine. This one appeared in the issue for August 1757. It extends from lat. 37°10' to 40°30' north, and from 74° to 80°10' west of London; and from 1°25' east to 4°40' west of Philadelphia. It has a scale of British state miles. The text at top reads “For the Lond: Mag:” The text at bottom reads “Printed for R. Baldwin in Pater Noster Row.”
Location
Currently not on view
date made
1757
ID Number
PH.317826
catalog number
317826
accession number
231759

Tall Clock Case with Blue-lacquer Case, about 1760

The Ryerson family, prominent 18th-century landowners in Brooklyn, New York, purchased this clock about 1760.
Description
The Ryerson family, prominent 18th-century landowners in Brooklyn, New York, purchased this clock about 1760. The imported clock, made in England in the third quarter of the eighteenth century, was a rarity in its time and signaled the purchasers’ wealth, taste and status in colonial society.
The clock features an eight-day, weight-driven brass movement that strikes the hours. The brass dial features a date aperture, a silvered chapter ring with Roman hour numerals and silvered signature plaque signed “Isaac Rogers/London.” The case features a blue finish made to imitate the then-mysterious techniques of Japanese and Chinese lacquer work.
Isaac Rogers had a trade establishment and watchmaking business at White Hart Court, Lombard Street, London. Timepieces for the Ottoman market were among his specialties. His son, also Isaac Rogers, succeeded him in business and became a master in the Worshipful Company of Clockmakers, London.
Reference:
Rogers, Isaac. The Dictionary of National Biography, 1897.
Location
Currently not on view (case fragments)
Currently not on view (dial frame)
Currently not on view
Currently not on view (pendulum; weights)
date made
ca 1760
maker
Rogers, Isaac
ID Number
1987.0852.01
catalog number
1987.0852.01
accession number
1987.0852

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