Measuring & Mapping

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.

After decades of experiments with the pendulum, Galileo Galilei (1564-1642) conceived of a pendulum clock that could be used to determine longitude at sea.
Description
After decades of experiments with the pendulum, Galileo Galilei (1564-1642) conceived of a pendulum clock that could be used to determine longitude at sea. Near the end of his life, blind and in failing health, he discussed the design with his son Vincenzio and his biographer Vincenzo Viviani. His son made a partial model and his biographer made or commissioned a drawing of the incomplete model after Galileo’s death.
The model in the Museum’s collection, made by New Jersey instrument maker Laurits Christian Eichner in 1958, is based on the seventeenth-century drawing preserved in the Biblioteca Nazionale Centrale, Florence, Italy. It is made of iron and features a pinwheel escapement and a pendulum.
During the seventeenth century, the problem of finding longitude at sea was among the leading topics in scientific research. The idea of using a precise clock to find longitude dated from the century before, but no such clock existed. Clocks in Galileo’s era told time only to the nearest quarter hour and allowed only crude rate regulation. The pendulum-regulated clock, first conceived by Galileo and then realized by Christian Huygens of the Netherlands in 1656, proved unsuitable for finding longitude on a rocking ship, and a good solution to the longitude problem would not appear until the marine chronometer at the end of the 18th century. But the pendulum clock revolutionized precise time for astronomy and other research by measuring time accurately to the second.
References:
1. Bedini, Silvio A. The Pulse of Time: Galileo Galilei, the Determination of Longitude, and the Pendulum Clock. Florence: Olschki, 1991.
2. Multhauf, Robert. Laurits Christian Eichner: Craftsman 1894-1967. Washington, D.C.: N. P., 1971.
3. Vanpaemel, G. “Science Distained: Galileo and the Problem of Longitude,” Italian Scientists in the Low Countries in the XVIIth and XVIIIth Centuries. Edited by C. S. Maffioli and L. C. Palm, 111-130. Amsterdam and Atlanta: Rodopi, 1989.
Location
Currently not on view
date made
1958
ID Number
ME.316158
catalog number
316158
accession number
224775
This instrument is a specialized timekeeper originally designed for finding longitude at sea and later used everywhere as a source of portable precise time.
Description
This instrument is a specialized timekeeper originally designed for finding longitude at sea and later used everywhere as a source of portable precise time. It has an English-made chronometer movement, finished by the firm William Bond & Son of Boston and fitted with the Bond break-circuit device, electrical equipment to permit the telegraphing of time signals. The Smithsonian’s Astrophysical Observatory used the instrument. The chronometer’s wooden box fits into a padded basket for extra protection.
Mechanism details:
Escapement: Earnshaw, spring detent, later pattern
Duration: 56-hour
Power source: Spring drive with chain and fuse
Bowl details:
Brass bowl
Brass gimbals
Bezel screwed and milled
Crystal flat and plain
Dial details:
Engraved and silvered brass
Indicates hours, minutes, seconds, winding level up and down, 24-hour dial
Inscription: "WM. BOND & SON, / Boston. No. 586" on dial; "WM. BOND & SON'S, BREAKCIRCUIT. / U. S. A." on silvered inside of bezel
Hands: Gold, spade, with blued seconds and Up & Down hands
Case details:
Box: solid wood, three-part, glazed center section
Brass corners
Mother of pearl key escutcheon
Inscriptions: "WM. BOND & SON. / Boston. No 521 / BREAK CIRCUIT" on nameplate
"BOND / 521" on small oval plate in bottom of box
Carrying case: Basket, with padding
References:
1. Gould, Rupert T. The Marine Chronometer. London: Holland Press, 1960.
2. Whitney, Marvin E. The Ship's Chronometer. Cincinnati: American Watchmakers Institute Press, 1985.
Location
Currently not on view
date made
ca 1870
maker
Wm. Bond & Son
ID Number
ME.314839
catalog number
314839
accession number
210897
This instrument is a specialized timekeeper designed for finding longitude at sea. Its form is that of the standardized 19th-century marine chronometer.
Description
This instrument is a specialized timekeeper designed for finding longitude at sea. Its form is that of the standardized 19th-century marine chronometer. Parkinson & Frodsham, a firm trading in high-quality chronometers, clocks and watches, was established in 1801 by William James Frodsham (1778-1850) and William Parkinson (d. about 1842). From 1801 to 1890, the firm’s business address was 4 Change Alley, and thereafter at other addresses until 1947.
Mechanism details:
Escapement: Earnshaw, spring detent
Duration: 56-hour
Power source: Spring drive with chain and fusee
Balance spring: Helical, blued steel, Earnshaw type
Inscription: "Parkinson & Frodsham." on backplate, "Change Alley / London" on barrel bridge
Bowl details:
Brass bowl
Brass gimbals
Bezel screwed and milled
Crystal convex and chamfered
Dial details:
Engraved and silvered brass
Indicates hours, minutes, seconds, winding level up and down
Hands: blued steel, early spade
Inscription: "Parkinson & Frodsham / Change Alley London. 2349"
Case details:
Box: solid wood, three-part, glazed center section
Brass corners, cartouche and key escutcheon
Roundel in bone
Inscriptions: none
References:
1. Gould, Rupert T. The Marine Chronometer. Essex: Holland Press, 1960.
2. Mercer, Tony. Chronometer Makers of the World. London: 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
ca 1840
maker
Parkinson & Frodsham
ID Number
ME.336641
catalog number
336641
accession number
1978.0161
catalog number
1978.0161.02
The Seiko Quartz Astron 35 SQ was the first quartz wristwatch on the market. The first commercially available quartz watch went on sale in Tokyo on Christmas Day in 1969.
Description
The Seiko Quartz Astron 35 SQ was the first quartz wristwatch on the market. The first commercially available quartz watch went on sale in Tokyo on Christmas Day in 1969. With a limited production run of only about 100 pieces, these watches had analog dials and sold for 450,000 yen ($1250), roughly the same price as a Toyota Corolla. The watches were manufactured in Suwa City, Japan, by the firm Suwa Seikosha (now Seiko Epson) and were marketed by the parent company K. Hattori & Co., Ltd.
The case and band on the Smithsonian example are a reproduction of those that originally came with Seiko’s 1969 wristwatch. Inside is an original module that contains a hybrid circuit (a combination of circuits on a single substrate, an intermediate step between discrete circuits and integrated circuits), a quartz oscillator with a frequency of 8,192 cycles per second and a miniature stepping motor for moving the hands. Seiko claimed the new watches were accurate to within plus or minus 5 seconds a month, a minute a year.
At the time of the Astron’s introduction, Seiko produced more mechanical watches than any other firm in the world. But company officials had been experimenting with quartz timekeeping since the late 1950s. Beginning in 1959, a team of engineers, under Tsuneya Nakamura, started to develop a quartz wristwatch. Their first quartz timekeepers were battery-powered chronometers, one of which was used in the Olympic Games in Tokyo in 1964. By 1967, Seiko engineers had miniaturized the timekeeper to produce a wristwatch prototype. To develop manufacturing techniques required another two years.
The Astron was the first public indicator that the wristwatch was about to be completely reinvented, with all-new electronic components. When battery-driven quartz wristwatches like the Astron first hit the market, it seemed unlikely that the new-fangled gadgets would sell. But electronic watches won over the buying public in a few short years.
Reference:
Stephens, Carlene and Maggie Dennis. “Engineering Time: Inventing the Electronic Wristwatch,” British Journal for the History of Science 33 (2000): pp. 477-497.
Location
Currently not on view
date made
1969
1998
manufacturer
Seiko Corporation
ID Number
1998.0248.01
catalog number
1998.0248.01
accession number
1998.0248
This is timing equipment from NASA's Goldstone Deep Space Communications Complex in the Mojave Desert near Barstow, Calif. It was installed at Goldstone about 1984.
Description
This is timing equipment from NASA's Goldstone Deep Space Communications Complex in the Mojave Desert near Barstow, Calif. It was installed at Goldstone about 1984. Based on specifications from NASA's Goddard Space Flight Center, the assembly was designed and made by TRAK Microwave of Tampa, Florida, and used at Goldstone to provide time codes for the ground station and space navigation until 2006. While in service, the assembly timed an impressive list of missions, including the two Voyagers launched in 1977 and the highly publicized Mars missions in 1996, 2001, 2003 and 2005. The equipment could track about thirty missions simultaneously and served about one hundred users.
The assembly contains three clocks—Clocks A, B and C (2008.0145.01, .02, and .03)—that work together as the master clock. Also known as a triple redundant clock, the three together "vote" on a single time of day, with agreement between two of the three determining the correct time. The master clock receives a reference frequency from a suite of atomic frequency standards (one primary and three backups). The master clock converts that frequency into time codes. Reference frequency signals and time codes are in turn distributed by the time insertion distribution system (2008.0145.04) to user locations in NASA's Deep Space Network for tracking spacecraft and radioastronomy experiments.
Time and frequency are essential to the Deep Space Network, a group of three communications facilities placed approximately 120 degrees apart around the world at Goldstone, near Madrid, Spain and near Canberra, Australia. The network synchronizes the three stations plus the Jet Propulsion Laboratory in Pasadena, CA, to an accuracy of microseconds through comparisons with each other and with time from the Global Positioning System.
Location
Currently on loan
date made
ca 1984
ID Number
2008.0145.01
accession number
2008.0145
catalog number
2008.0145.01
This clock was built at the U. S. Naval Observatory about 1936 as part of an experimental program to control time signals transmitted by radio. It is a quartz clock, that is, it depends on a specially cut piece of quartz crystal to keep time.
Description
This clock was built at the U. S. Naval Observatory about 1936 as part of an experimental program to control time signals transmitted by radio. It is a quartz clock, that is, it depends on a specially cut piece of quartz crystal to keep time. The search for a better timekeeper than the best pendulum clocks led to the development of quartz-crystal clocks, the first of which telecommunications engineers at Bell Telephone Laboratories built in 1927 to monitor and control frequencies.
Location
Currently not on view
date made
1936
ID Number
ME.319994
catalog number
319994
accession number
240411
The Magellan Corporation, founded in 1986, worked to develop a handheld, battery-powered GPS receiver for the civilian market. Launched in 1988, the NAV 1000 was the first hand-held receiver introduced to the consumer market.
Description
The Magellan Corporation, founded in 1986, worked to develop a handheld, battery-powered GPS receiver for the civilian market. Launched in 1988, the NAV 1000 was the first hand-held receiver introduced to the consumer market. Magellan anticipated that people would use these devices for hiking, boating and other recreational purposes.
Location
Currently not on view
date made
1988
maker
Magellan Systems Corporation
ID Number
2010.0118.01
accession number
2010.0118
catalog number
2010.0118.01
In the 19th century, portable marine timekeepers called chronometers became indispensable instruments for determining longitude at sea.
Description
In the 19th century, portable marine timekeepers called chronometers became indispensable instruments for determining longitude at sea. To use a marine chronometer, outbound sailors would set their timepieces to the time of a known port's longitude—say Greenwich, England, or Boston. Once at sea, mariners calculated their position east or west of that place by converting the difference in time on the chronometer and local ship time into distance, 15 degrees of longitude for every hour.
Tradition says this timekeeper was the first seagoing chronometer made in America. Twenty-three-year-old Boston clockmaker William Cranch Bond constructed it during the War of 1812. When Bond made his instrument, no chronometer industry existed in the United States, and British makers dominated the world market.
Bond's instrument went to sea only once, on a voyage to Sumatra in 1818 aboard the U.S. Navy vessel Cyrus. Chronometers were uncommon aboard American ships at the time, and the Cyrus's captain warned Bond to read the record of the instrument's performance with a critical eye.
Invented half a century earlier by John Harrison in England and Pierre LeRoy and Ferdinand Berthoud in France, the chronometer by Bond's time had already assumed standard features. Most of the chronometers ran from the force of an unwinding spring and had a special feature—the detent escapement. Suspended from gimbals in a wooden box, the instrument remained horizontal even on a heaving ship. Bond's timekeeper was different. Unable or unwilling to get British spring steel in wartime, he borrowed an 18th-century Berthoud design and built his timekeeper to run with power from a falling weight.
William Bond & Son, a family firm begun by William Cranch Bond's father in 1793, became one of America's best-known chronometer dealers. As the business flourished, the younger Bond pursued his passion for astronomy. In 1839 he became the first director of the Harvard College Observatory.
Location
Currently not on view (case; sign)
Currently not on view
date made
ca 1812-1815
maker
Bond, William C.
ID Number
ME.318981
catalog number
318981
accession number
230288
The Magellan Systems Corporation produced some of the earliest handheld GPS units for civilian use. In 1986 company engineers began experimenting with electronic mockups. This is the earliest keyboard.
Description
The Magellan Systems Corporation produced some of the earliest handheld GPS units for civilian use. In 1986 company engineers began experimenting with electronic mockups. This is the earliest keyboard. Together with the "breadboard" (2010.0154.01) and power supply (2010.0154.03), this object was used to test circuitry and components at Magellan while developing the first civilian GPS receiver.
Location
Currently not on view
maker
Magellan Systems Corporation
ID Number
2010.0154.02
accession number
2010.0154
catalog number
2010.0154.02
This instrument is a specialized timekeeper for determining longitude at sea. It is serial no. 1 from a run of approximately 10,000 similar timekeepers made by Hamilton Watch Co, Lancaster, PA in 1942.World War II created a dire chronometer shortage for the United States.
Description
This instrument is a specialized timekeeper for determining longitude at sea. It is serial no. 1 from a run of approximately 10,000 similar timekeepers made by Hamilton Watch Co, Lancaster, PA in 1942.
World War II created a dire chronometer shortage for the United States. Before the war, most chronometers for American military and civilian customers were imported. Only a few American firms—including William Bond & Son of Boston and the New York establishments of John Bliss Inc. and T.S. and J. D. Negus—finished chronometers from parts imported from European makers. Chronometer making was a craft, with only a few hundred produced in any given year. When the war started in 1941, European suppliers of parts and finished instruments halted exports to the United States.
Anticipating the arrival of war, the U.S. Naval Observatory had asked American domestic watch manufacturers in 1939 for their participation in mass-producing chronometers. Domestic watch manufacturers Hamilton and Elgin agreed to undertake the design and production, but only Hamilton’s product met Navy accuracy requirements. Hamilton delivered two prototypes to the Navy on 27 February 1942, which passed with an error rate of 1.55 seconds per day. The firm went on during the war to mass-produce 8900 more chronometers for the Navy, 1500 for merchant shipping and 500 for the Army. Between 1942 and 1944, the price dropped from $625 to $390 per timekeeper.
Hamilton’s design for its Model 21 chronometer did not copy traditional European standards. Instead the design introduced key changes to improve accuracy. The modifications included changes to the escapement and the chronometer’s oscillating unit—the balance and hairspring assembly.
To find longitude at sea, a chronometer would be set to the time of a place of known longitude, like Greenwich, England, the prime meridian. 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.
References:
1. Dick, Steven J. Sky and Ocean Joined: The U. S. Naval Observatory 1830-2000. Cambridge: Cambridge University Press, 2003.
2. Whitney, Marvin. The Ship’s Chronometer. Cincinnati: American Watchmakers Institute Press, 1985.
Location
Currently not on view
date made
1941
1956
maker
Hamilton
ID Number
ME.314825
catalog number
314825
accession number
210893
Edwin A. Link, Jr. presented this bubble sextant, in a beautiful alligator case, to P. V. H. Weems. It is a standard A-12 with an attachment that enables the user to view the real horizon.
Description
Edwin A. Link, Jr. presented this bubble sextant, in a beautiful alligator case, to P. V. H. Weems. It is a standard A-12 with an attachment that enables the user to view the real horizon. Link applied for a patent on this feature in 1943.
Ref: Link Bubble Sextant (Octant) Model A-12 Handbook: Description, Operation, Use, Adjustment (Binghamton, N.Y.: Link Aviation Devices, Inc., 1943).
Edwin A. Link, Jr., "Navigation Instrument Including a Horizon Attachment," U.S. patent #2,395,559
Location
Currently not on view
user
Weems, Philip Van Horn
ID Number
AF.59061-N
catalog number
59061-N
accession number
242229
Octant with a rosewood frame, flat brass index arm, and ivory name plate. The ivory scale is graduated every 20 minutes from -5° to +95° and read by vernier to single minutes of arc.
Description
Octant with a rosewood frame, flat brass index arm, and ivory name plate. The ivory scale is graduated every 20 minutes from -5° to +95° and read by vernier to single minutes of arc. The "Andw Newell Maker Boston" inscription refers to Andrew Newell (1751-1798), a mathematical instrument maker in Boston. Inside the box is the trade card of David Baker, proprietor of a nautical instrument shop in New Bedford during the second quarter of the nineteenth century.
Location
Currently not on view
date made
ca 1800
maker
Newell, Andrew
ID Number
1991.0140.01.01
catalog number
1991.0140.01.01
accession number
1991.0140
This unit is all that remains of a quartz clock dating from about 1955. The original clock consisted of additional components—a quartz oscillator, power supply and a frequency divider—mounted with this dial unit on an electronics rack.
Description
This unit is all that remains of a quartz clock dating from about 1955. The original clock consisted of additional components—a quartz oscillator, power supply and a frequency divider—mounted with this dial unit on an electronics rack. It was developed at the Naval Research Laboratory and installed at the U.S. Naval Observatory to monitor the accuracy of time signals sent to naval radio stations at Annapolis, San Francisco, Hawaii and Balboa in the Panama Canal Zone. The time signal started at the Naval Observatory, traveled by telegraph line to Annapolis and moved by radio relay to the remote stations. Similar transmitting quartz clocks were later installed at each of the stations, and the observatory’s role shifted from transmitting signals to monitoring the signal accuracy from the stations and providing published corrections based on comparisons with observatory standards.
This surviving component is an electromechanical clock with a twenty-four-hour dial, a synchronous motor, an elaborate system of oilers and a strobe system for checking radio signal accuracy. The grey-painted face plate has an identification tag reading: “TD-31/FSM-5/Clock/Serial 1/A UNIT OF TIME STANDARD AN/FSM-5 /MANUFSCTURED FOR NAVY BUREAU OF SHIPS/BY/U.S. NAVAL OBSERVATORY/WASHINGTON DC.” At lower left is a switch and a tape label marked: “PANAMA ONLY.” Nearby in pencil: “Amber.” On the lower right is a brass crank for resetting the clock and a five-digit counter. Above the crank is an eyepiece. The eyepiece gives a low-power microscopic view into the clock movement where a glass dial, engraved with a thousand divisions revolves once a second. It is possible to read the thousandth of a second from the flash provided by an adjacent strobe lamp. The lamp flashes are controlled by another clock or by radio signals.
Beginning in 1934, the U.S. Naval Observatory started to acquire quartz clocks to serve as time standards and to transmit time signals to navy radio stations. In this kind of clock, first built at Bell Telephone Laboratories in 1927, a small crystal of quartz takes the place of a pendulum or balance wheel. The crystal vibrates between 50,000 to 100,000 times per second, with a rate that depends upon how the crystal is cut. Through an electric current, that frequency drives a clock with a synchronous motor. The clock’s gearing divides down the crystal vibrations to a rate that turns the hands. Similar to other observatories, quartz clocks replaced the best pendulum clocks as time standards from 1946 to 1966, when atomic clocks were accepted.
References:
1. Gebhard, Louis A. Evolution of Naval Radio-Electronics and Contributions of the Naval Research Laboratory, NRL Report 8300 (Washington, DC: GPO, 1979).
2. Dick, Steven. Sky and Ocean Joined: The U.S. Naval Observatory 1830-2000. Cambridge, UK: Cambridge University Press, 2003.
Location
Currently not on view
ID Number
1989.0581.01
catalog number
1989.0581.01
accession number
1989.0581
The Defense Advanced GPS Receiver (DAGR) is a small, hand-held GPS receiver made by Rockwell-Collins, Inc. The DAGR uses state of the art GPS technology, including "All in View" satellite tracking and the Selective Availability Anti-Spoofing Module (SAASM).
Description
The Defense Advanced GPS Receiver (DAGR) is a small, hand-held GPS receiver made by Rockwell-Collins, Inc. The DAGR uses state of the art GPS technology, including "All in View" satellite tracking and the Selective Availability Anti-Spoofing Module (SAASM). The SAASM allows decryption of precision GPS coordinates. The size and weight (5 oz) provide for pocket storage and easy portability.
Initial contracting for the production of the DAGR began in 2002. Actual use in the field began in 2004. It is used by the US Armed Services, the Missile Defense Agency, the National Geospatial-Intelligence Agency and 32 Allied countries.
Location
Currently not on view
ID Number
2012.0002.01
accession number
2012.0002
catalog number
2012.0002.01
This Precision Lightweight GPS Receiver (PLGR) was made by Rockwell Collins between 1993 and 2005. It is a handheld, five-channel, single-frequency GPS receiver designed to be used by the U.S. military to display position, velocity and time of day.
Description
This Precision Lightweight GPS Receiver (PLGR) was made by Rockwell Collins between 1993 and 2005. It is a handheld, five-channel, single-frequency GPS receiver designed to be used by the U.S. military to display position, velocity and time of day. It is generally referred to as a “plugger” or “handpack.” It has an antenna, keyboard, backlit display, receiver processor unit and memory battery. It operates off either a power battery or an external power source. Designed for use anywhere in the world, it is watertight and can be used with night-vision goggles. The unit is designed to be held in the left hand and operated with the left thumb. The jacks on the unit allow it to be installed in a fixed location as well as on moving vehicles. When operated in the ”time-only” mode it can calculate time to less than 100 nanoseconds. This instrument essentially replaced the PSN-8 Manpack GPS receiver that the U.S. military used in Desert Storm.
Reference:
Rockwell Collins Government Systems, “PLGR-96 Precision Lightweight GPS Receiver,” Navigation and Landing Systems January 1, 2001.
Location
Currently not on view
maker
Collins Avionics & Communications Division of Rockwell International
ID Number
1997.0006.02
accession number
1997.0006
catalog number
1997.0006.02
One of six ships of the U.S. Exploring Expedition, the Porpoise sailed around the world between 1838 and 1842 under the command of Lt. Cadwallader Ringgold. The four-year-long expedition, headed by Lt.
Description
One of six ships of the U.S. Exploring Expedition, the Porpoise sailed around the world between 1838 and 1842 under the command of Lt. Cadwallader Ringgold. The four-year-long expedition, headed by Lt. Charles Wilkes, covered nearly 87,000 miles, including a full circumnavigation of the globe. Wilkes and his crew sighted Antarctica (proving its existence), charted hundreds of Pacific islands and surveyed the Columbia River in present-day Oregon.
This model was built in the 1980s by Dr. William Brown for an exhibition about the U.S. Exploring Expedition at the Smithsonian’s National Museum of Natural History.
Location
Currently not on view
ID Number
1985.0485.01
accession number
1985.0485
catalog number
1985.0485.01
This instrument is a specialized timekeeper for finding longitude at sea. Thomas Earnshaw made this chronometer in England about 1798.
Description
This instrument is a specialized timekeeper for finding longitude at sea. Thomas Earnshaw made this chronometer in England about 1798. It became part of the James Arthur Collection at New York University, and the university donated a portion of the collection, including this 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.
Thomas Earnshaw (1749-1829) was a pioneer in chronometer development. He is credited with introducing to chronometer design two important features that became standard parts of the timekeeper in the 19th century—the detached detent escapement and, independently of his rival John Arnold, the bimetallic compensation balance. His simplifications permitted others to undertake batch production of chronometers, and his work received an award of £2500 from Britain’s Longitude Board in 1805.
Mechanism details:
Escapement: Earnshaw spring detent
Duration: 1 day
Power source: Spring drive with chain and fuse
Balance spring: helical, blued steel
Balance: Earnshaw, two-arm
Inscription: “Thos. Earnshaw / Inv. Et Fecit No. 451” on back plate
Barrel bridge possibly a replacement
Dial details:
Engraved and silvered brass
Indicates hours, minutes, seconds
Inscription: “Thos. Earnshaw / INVT. ET FACIT /No. 451” on dial
Blued steel lunette hands (minute hand is a replacement)
Brass bowl; screwed and milled bezel; convex and chamfered crystal
No box
No winding key
References:
1. Mercer, Tony. Chronometer Makers of the World. Essex: NAG Press and Tony Mercer, 1991.
2. Thompson, David. Clocks. London: British Museum Press, 2005.
3. Whitney, Marvin E. The Ship’s Chronometer. Cincinnati: American Watchmakers Institute Press, 1985.
Location
Currently not on view
date made
ca 1798
maker
Earnshaw, Thomas
ID Number
1984.0416.013
accession number
1984.0416
catalog number
1984.0416.013
This is timing equipment from NASA's Goldstone Deep Space Communications Complex in the Mojave Desert near Barstow, Calif. It was installed at Goldstone about 1984.
Description
This is timing equipment from NASA's Goldstone Deep Space Communications Complex in the Mojave Desert near Barstow, Calif. It was installed at Goldstone about 1984. Based on specifications from NASA's Goddard Space Flight Center, the assembly was designed and made by TRAK Microwave of Tampa, Florida, and used at Goldstone to provide time codes for the ground station and space navigation until 2006. While in service, the assembly timed an impressive list of missions, including the two Voyagers launched in 1977 and the highly publicized Mars missions in 1996, 2001, 2003 and 2005. The equipment could track about thirty missions simultaneously and served about one hundred users.
The assembly contains three clocks—Clocks A, B and C (2008.0145.01, .02, and .03)—that work together as the master clock. Also known as a triple redundant clock, the three together "vote" on a single time of day, with agreement between two of the three determining the correct time. The master clock receives a reference frequency from a suite of atomic frequency standards (one primary and three backups). The master clock converts that frequency into time codes. Reference frequency signals and time codes are in turn distributed by the time insertion distribution system (2008.0145.04) to user locations in NASA's Deep Space Network for tracking spacecraft and radioastronomy experiments.
Time and frequency are essential to the Deep Space Network, a group of three communications facilities placed approximately 120 degrees apart around the world at Goldstone, near Madrid, Spain and near Canberra, Australia. The network synchronizes the three stations plus the Jet Propulsion Laboratory in Pasadena, CA, to an accuracy of microseconds through comparisons with each other and with time from the Global Positioning System.
Location
Currently on loan
date made
ca 1984
ID Number
2008.0145.04
accession number
2008.0145
catalog number
2008.0145.04
The Outback Sts is a GPS-based farming system designed to provide precision guidance for farm machinery.
Description
The Outback Sts is a GPS-based farming system designed to provide precision guidance for farm machinery. The system was manufactured in 2012 by Hemisphere GPS (renamed AgSolution in 2013), a company headquartered in Calgary, Alberta, Canada.
Roy Bardole used this touch-screen computer and a GPS antenna to receive enhanced GPS signals for working corn and soybean acreage in Iowa. With the equipment, he could set a work area perimeter, instruct tractors and implements to steer automatically on either a straight or contoured path, and log data about the work accomplished.
Satellite navigation helps farmers meet the challenge of increasing crop yields and lowering costs. They can use precise positioning to plant and harvest faster and more efficiently than ever before, and by applying fertilizers and pesticides more precisely, they can reduce the environmental impact of raising crops.
Location
Currently not on view
maker
Hemisphere GPS. Outback Guidance Division
ID Number
2012.0221.02
catalog number
2012.0221.02
accession number
2012.0221
maker number
902-1049-000#_0912
serial number
1100188
This instrument is a specialized timekeeper for finding longitude at sea. It was made by the firm Robert Molyneux & Sons of London, England, between 1832 and 1845. The U.S.
Description
This instrument is a specialized timekeeper for finding longitude at sea. It was made by the firm Robert Molyneux & Sons of London, England, between 1832 and 1845. The U.S. Navy Bureau of Ships transferred it to the Smithsonian in 1953.
To find longitude at sea, a chronometer would be set to the time of a place of known longitude, like Greenwich, England, the prime meridian. 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.
Robert Molyneux was a maker of chronometers and precision clocks in England. He was trained by Thomas Earnshaw and went into business for himself in the 1820s. In 1832 he moved his London business from 44 Devonshire Street to 30 Southampton Row and partnered with his son Henry in 1835. In 1842 the chronometer firm Birchall & Appleton moved to that address.
Mechanism details:
Escapement: Earnshaw spring detent
Duration: 56-hour
Power source: Spring drive with chain and fuse
Balance spring: helical, blued steel
Dial details:
Engraved and silvered brass
Indicates hours, minutes, seconds, and winding level up and down
Inscription: “Molyneux & Sons / 30 Southampton Row, London / No 1436 / U.S. Army.”
Blued steel spade hands
Brass bowl with fittings to insert in gimbal
No box
No winding key
References:
1. Britten, Frederick James. Old Clocks and Watches & Their Makers. London: E. & N. Spon Limited, 1922.
2. Gould, Rupert T. The Marine Chronometer. London: Holland Press, 1960.
3. Mercer, Tony. Chronometer Makers of the World. Essex: N.A.G. Press, 1991.
4. Whitney, Marvin. The Ship’s Chronometer. Cincinnati: American Watchmakers Institute Press, 1985.
5. Wood, Christopher. “Robert Molyneux's Astronomical Clocks and Chronometers,” Antiquarian Horology 9 no. 4 (1975).
Location
Currently not on view
date made
1835-1842
maker
Molyneaux & Sons
ID Number
ME.314266
catalog number
314266
accession number
198140
Bracket clock, Dutch, last quarter of the 17th centuryJohannes Van Ceulen made this clock in The Hague, Holland, in collaboration with Christiaan Huygens.
Description
Bracket clock, Dutch, last quarter of the 17th century
Johannes Van Ceulen made this clock in The Hague, Holland, in collaboration with Christiaan Huygens. Huygens (1629-1693) patented the design for the first practical pendulum clock in 1657.
In common with other so-called “Hague clocks,” which were made in several Dutch cities and by other clockmakers in Huygens’ time, this Van Ceulen clock has a single spring that drives both time and strike trains, a pendulum suspended between curved “cycloidal cheeks” (designed to correct the oscillation period of the pendulum for variations in its swing’s amplitude) and an ebonized fruitwood case reminiscent of classical architecture. The pediment of the case, with its gilt floral pattern, serves not only a decorative function, but also conceals the clock’s externally mounted bell. Also typical are the velvet-covered brass dial plate and the prominent figure of Chronos, or Father Time. The figure supports the chapter ring and rests on two signature plaques inscribed “Johannes Van/Ceulen Haghe.” The backplate is also marked “Johannes Van Ceulen/Fecit Haghe.” This clock has a two-day movement, verge and crown wheel escapement with crutch, silk thread suspension for the pendulum and count wheel striking. The alarm work is missing.
References:
1. Mahoney, Michael S. “Christian Huygens: The Measurement of Time and of Longitude at Sea,” in Studies on Christiaan Huygens, Edited by H.J.M. Bos et al. (Lisse: Swets, 1980), 234-270.
2. Plomp, R. Spring-Driven Dutch Pendulum Clocks, 1657-1710. Schiedam: Interbook International B.V., 1979.
Location
Currently on loan
date made
late 17th century
ID Number
1984.0416.004
accession number
1984.0416
catalog number
1984.0416.004
This is timing equipment from NASA's Goldstone Deep Space Communications Complex in the Mojave Desert near Barstow, Calif. It was installed at Goldstone about 1984.
Description
This is timing equipment from NASA's Goldstone Deep Space Communications Complex in the Mojave Desert near Barstow, Calif. It was installed at Goldstone about 1984. Based on specifications from NASA's Goddard Space Flight Center, the assembly was designed and made by TRAK Microwave of Tampa, Florida, and used at Goldstone to provide time codes for the ground station and space navigation until 2006. While in service, the assembly timed an impressive list of missions, including the two Voyagers launched in 1977 and the highly publicized Mars missions in 1996, 2001, 2003 and 2005. The equipment could track about thirty missions simultaneously and served about one hundred users.
The assembly contains three clocks—Clocks A, B and C (2008.0145.01, .02, and .03)—that work together as the master clock. Also known as a triple redundant clock, the three together "vote" on a single time of day, with agreement between two of the three determining the correct time. The master clock receives a reference frequency from a suite of atomic frequency standards (one primary and three backups). The master clock converts that frequency into time codes. Reference frequency signals and time codes are in turn distributed by the time insertion distribution system (2008.0145.04) to user locations in NASA's Deep Space Network for tracking spacecraft and radioastronomy experiments.
Time and frequency are essential to the Deep Space Network, a group of three communications facilities placed approximately 120 degrees apart around the world at Goldstone, near Madrid, Spain and near Canberra, Australia. The network synchronizes the three stations plus the Jet Propulsion Laboratory in Pasadena, CA, to an accuracy of microseconds through comparisons with each other and with time from the Global Positioning System.
Location
Currently on loan
date made
ca 1984
ID Number
2008.0145.02
accession number
2008.0145
catalog number
2008.0145.02
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
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

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