Measuring & Mapping - Overview
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.
"Measuring & Mapping - Overview" showing 108 items.
Page 1 of 11
"American Method in Astronomical Observation"
- Description
- From its infancy, timekeeping has depended on astronomy. The motion of celestial bodies relative to the rotating Earth provided the most precise measure of time until the mid-twentieth century, when quartz and atomic clocks proved more constant. Until that time, mechanical observatory clocks were set and continuously corrected to agree with astronomical observations.
- The application of electricity to observatory timepieces in the late 1840s revolutionized the way American astronomers noted the exact movement of celestial events. U.S. Coast Survey teams devised a method to telegraph clock beats, both within an observatory and over long distances, and to record both the beats and the moment of observation simultaneously. British astronomers dubbed it the "American method of astronomical observation" and promptly adopted it themselves.
- Transmitting clock beats by telegraph not only provided astronomers with a means of recording the exact moment of astronomical observations but also gave surveyors a means of determining longitude. Because the Earth rotates on its axis every twenty-four hours, longitude and time are equivalent (fifteen degrees of longitude equals one hour).
- In 1849 William Cranch Bond, then director of the Harvard College Observatory, devised an important improvement for clocks employed in the "American method." He constructed several versions of break-circuit devices—electrical contracts and insulators attached to the mechanical clock movement—for telegraphing clock beats once a second. The Bond regulator shown here incorporates such a device. Bond's son Richard designed the accompanying drum chronograph, an instrument that touched a pen to a paper-wrapped cylinder to record both the beats of the clock and the instant of a celestial event, signaled when an observer pressed a telegraph key.
- Location
- Currently not on view
- Date made
- ca 1850
- maker
- William Bond & Son
- ID Number
- 1981.0322.01
- accession number
- 1981.0322
- catalog number
- 1981.0322.01
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Chemical Balance
- Description
- This chemical balance was made by Aaron Pollock of Boston. It was used in the laboratory of Ira Remsen (1846–1927), who became the first professor of chemistry at Johns Hopkins University in 1876. The size of the pans indicates that this balance was used for gross preparation. The balance is made of brass, with bearings of steel and agate. The pans are copper. The cabinet is mahogany with glass-paneled doors and glass panels in the back. Chemical balances are usually contained in cabinets because their operation is affected by air changes and humidity. The drawer beneath the pillar contains the weights.
- Location
- Currently not on view
- patentee
- Pollock, Aaron
- used by
- Remsen, Ira
- maker
- Pollock, Aaron
- ID Number
- CH*315866.1
- catalog number
- 315866.1
- accession number
- 221777
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Chronograph
- Description
- From its infancy, timekeeping has depended on astronomy. The motion of celestial bodies relative to the rotating Earth provided the most precise measure of time until the mid-twentieth century, when quartz and atomic clocks proved more constant. Until that time, mechanical observatory clocks were set and continuously corrected to agree with astronomical observations.
- The application of electricity to observatory timepieces in the late 1840s revolutionized the way American astronomers noted the exact movement of celestial events. U.S. Coast Survey teams devised a method to telegraph clock beats, both within an observatory and over long distances, and to record both the beats and the moment of observation simultaneously. British astronomers dubbed it the "American method of astronomical observation" and promptly adopted it themselves.
- Transmitting clock beats by telegraph not only provided astronomers with a means of recording the exact moment of astronomical observations but also gave surveyors a means of determining longitude. Because the Earth rotates on its axis every twenty-four hours, longitude and time are equivalent (fifteen degrees of longitude equals one hour).
- In 1849 William Cranch Bond, then director of the Harvard College Observatory, devised an important improvement for clocks employed in the "American method." He constructed several versions of break-circuit devices—electrical contracts and insulators attached to the mechanical clock movement—for telegraphing clock beats once a second. The Bond regulator shown in the forground incorporates such a device. Bond's son Richard designed the accompanying drum chronograph, an instrument that touched a pen to a paper-wrapped cylinder to record both the beats of the clock and the instant of a celestial event, signaled when an observer pressed a telegraph key.
- Location
- Currently not on view
- Date made
- ca 1868
- maker
- William Bond & Son
- ID Number
- ME*318759
- catalog number
- 318759
- accession number
- 230288
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Earth Inductor
- Description
- This instrument is marked "MAX KOHL Werkstätten für Prazisions Mechanick CHEMNITZ I.S." and "CENTRAL SCIENTIFIC CO. LABORATORY APPARATUS CHICAGO U.S.A." Kohl described it as an "Earth Inductor after Palmieri...with round frame 300 mm diameter, with 100 turns of 1 mm thick wire, with commutator." Luigi Palmieri was a physicist in Naples who, in the 1840s, developed an earth inductor with elliptical ring that rotated around its longer axis. The Palmieri apparatus with a circular ring, as in this example, seems to have originated in the 1860s.
Max Kohl was in business as a scientific instrument maker from 1876 to 1937. The Central Scientific Co. was established in 1900. This example belonged to Trinity College in Hartford, Conn., and came to the Smithsonian in 1981.
Ref: Max Kohl, Physical Apparatus (Chemnitz, 1926), p. 974.
- maker
- Max Kohl
- ID Number
- 1981.0743.04
- accession number
- 1981.0743
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Conversion Factors, Reference Table for Engineers and Other Executives
- Description
- This battered table, printed on heavy green paper, gives an alphabetical list of units of measure, conversion factors, and new units of measure. For example, for the unit of measure centimeters, the conversion factor is 0.3937. Multiplying a measurement in centimeters by the conversion factor gives a result in inches.
- The table was distributed by Precision Equipment Company of Chicago, Illinois. The back of the table advertises the company’s shelving and safety steps. A sentence at the bottom of the chart reads: Reproduced with the Permission of Foxboro Co. and Exporters’ Digest.
- The owner of the table inserted a row with the conversion factor of 1.151 for converting from nautical miles to statute miles.
- Exporters’ Digest was published from 1927 through 1958. Foxboro Company was in business from 1912 through 1990. A surviving piece of trade literature suggests that the Precision Equipment Company was in business in the 1950s. Hence the rough date of 1950 assigned to the object.
- Location
- Currently not on view
- date made
- ca 1950
- ID Number
- 1981.0922.16
- accession number
- 1981.0922
- catalog number
- 1981.0922.16
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Declinometer
- Description
- A declinometer measures the horizontal angle between the geographic and magnetic poles of the earth (also known as the declination, or variation, of the magnetic needle). This particular form was introduced by H. P. Gambey of Paris in the 1830s and remained popular in France throughout the century. This example was purchased in France and was probably produced there as well. It consists of a heavy stone base, a bar magnet supported by a thread, and microscopes at either end to read the magnet's position.
Ref: E. Mascart, Traité de Magnétism Terrestre (Paris, 1900), p. 189-190.
- Date made
- ca 1830-1845
- maker
- Gambey, Henri Prudence
- ID Number
- 1982.0668.01
- accession number
- 1982.0668
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Magnetometer
- Description
- This instrument, a lighter and more robust version of the standard unifilar magnetometer used at the Kew Observatory, was designed by H. A. Denholm Fraser for the Magnetic Survey of India. Features include scales graduated on optical glass, and a phosphor-bronze ribbon to suspend the magnet. This example is marked "T. COOKE & SONS LTD. LONDON & YORK. No. 26" and "U.S.C.& G.S. No. 40." It was used at the U.S. Coast and Geodetic Survey's magnetic observatory in Honolulu from 1927 to the 1950s. The U.S. Geological Survey acquired it in 1973, when it took over the geomagnetic program of the federal government, and transferred it to the Smithsonian in 1982.
- Thomas Cooke began in business in York, England, in 1837. The firm became T. Cooke & Sons in 1868, and T. Cooke & Sons Ltd. in 1897. A merger with Troughton & Simms Ltd. in 1922, led to the formation of Cooke, Troughton & Simms Ltd.
- Photograph 82-15291 shows this magnetometer fitted with the induction apparatus developed by J. H. Nelson in 1938.
- Ref: H. A. Denholm Fraser, "The Unifilar Magnetometer of the Magnetic Survey of India," Terrestrial Magnetism 6 (1901): 65-69.
- T. Cooke & Sons, Illustrated Catalogue of Surveying Instruments, etc. (London, 1907), pp. 62-63.
Anita McConnell, Instrument Makers to the World. A History of Cooke, Troughton & Simms (York, 1992), pp. 69-70.
- maker
- T. Cooke & Sons Ltd.
- ID Number
- 1982.0671.02
- accession number
- 1982.0671
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Universal Magnetometer with Dip Circle
- Description
- This instrument is marked "D.T.M. C.I.W. N° 19." Designed and built by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington in 1912, it incorporates an astronomical telescope and magnetometer for the determination of magnetic declination and horizontal intensity, and a dip circle with a Lloyd-Creak attachment for the determination of inclination and intensity. It is relatively light and easy to manipulate. It was used for a few years and then set aside when the universal magnetometer with earth inductor came into use.
- This magnetometer was probably transferred to the U.S. Coast and Geodetic Survey after the Carnegie Institution closed its geomagnetic program. The U.S. Geological Survey acquired it in 1973, when it took over the geomagnetic program of the federal government, and transferred it to the Smithsonian in 1982.
- Ref: J. A. Fleming, "Two New Types of Magnetometers Made by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington," Terrestrial Magnetism 16 (1911): 1-12.
- Carnegie Institution of Washington, Land Magnetic Observations, 1911-1913 (Washington, D.C., 1915), pp. 7-8.
- Date made
- 1912
- maker
- Carnegie Institution of Washington. Department of Terrestrial Magnetism
- ID Number
- 1982.0671.03
- accession number
- 1982.0671
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Earth Inductor
- Description
- As scientists discovered that even the best dip circles gave unreliable results, they began using earth inductors to determine magnetic dip. In 1912, the Department of Terrestrial Magnetism of the Carnegie Institution of Washington developed a new earth inductor for use at sea. It has three key elements: an improved gimbal stand, a means for rotating the coil without disturbing the gimbal rings, and a sensitive galvanometer.
- This example is marked "D.T.M. C.I.W. E.I. N° 3." It is the third Carnegie marine earth inductor. When the Carnegie closed its program in terrestrial magnetism, it was lent to the U.S. Coast and Geodetic Survey. The U.S. Geological Survey acquired it in 1973 when it took over the geomagnetic program of the federal government, and transferred it to the Smithsonian in 1982.
- Ref: J. A. Fleming, "Description of the C.I.W. Marine Earth
- Inductor," Terrestrial Magnetism 18 (1912): 39-45.
- C. W. Hewlett, "Report on the C.I.W. Marine Earth Inductor," Terrestrial Magnetism 18 (1912): 46-48.
- Date made
- 1912
- maker
- Carnegie Institution of Washington. Department of Terrestrial Magnetism
- ID Number
- 1982.0671.05
- accession number
- 1982.0671
- Data Source
- National Museum of American History, Kenneth E. Behring Center
Universal Magnetometer with Earth Inductor
- Description
- This instrument was designed and produced by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington. Unlike the Carnegie's original universal magnetometer, this one is equipped with an earth inductor to determine dip. It is marked "DEPARTMENT TERRESTRIAL MAGNETISM Carnegie Institution of Washington E.I. - M. No. 28." It was completed in 1914 and used in many locations around the world. The U.S. Coast and Geodetic Survey used it in South and Central America in the early 1940s. The U.S. Geological Survey acquired it in 1973, when that agency took charge of the federal program in geomagnetism, and transferred it to the Smithsonian in 1982.
- Ref: J. A. Fleming and J. A. Widner, "Description of the C.I.W. Combined Magnetometer and Earth Inductor," Terrestrial Magnetism 18 (1913): 105-110.
- Carnegie Institution of Washington. Department of Terrestrial Magnetism. Land Magnetic Observations, 1911-1913 (Washington, D.C., 1915), pp. 9-12.
- U. S. Coast and Geodetic Survey, Magnetic Observations in the American Republics 1941-44 (Washington, D.C., 1946), p. 16.
- Date made
- 1914
- maker
- Carnegie Institution of Washington. Department of Terrestrial Magnetism
- ID Number
- 1982.0671.07
- accession number
- 1982.0671
- Data Source
- National Museum of American History, Kenneth E. Behring Center
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