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.

Dry Card Compass

This nautical dry-card compass has a turned wooden bowl gimbal mounted in a wooden box. It probably dates from the middle decades of the nineteenth century. The inscription reads "C. R. SHERMAN & Co. NEW BEDFORD." Charles R. Sherman (fl.
Description
This nautical dry-card compass has a turned wooden bowl gimbal mounted in a wooden box. It probably dates from the middle decades of the nineteenth century. The inscription reads "C. R. SHERMAN & Co. NEW BEDFORD." Charles R. Sherman (fl. 1865-1905) sold instruments and other items for nautical use.
Location
Currently not on view
date made
1865-1905
maker
Sherman, Charles R.
ID Number
1995.0035.02
accession number
1995.0035
catalog number
1995.0035.02

Révy Water Current Meter

“Messrs.
Description
“Messrs. Elliott Bros., of London, made our meters, and are acquainted with all requirements: they charge about ten guineas for the complete instrument.” So wrote Julien John Révy, an Austrian civil engineer living in England, in his 1874 account of his survey of the Panama and Uruguay rivers in South America.
Elliott Bro. showed a Révy water current meter at the Special Loan Collection of Scientific Instruments held in London in 1876, noting that it was made “for measuring the velocity of currents in large rivers.” The firm went on to explain that “The spherical boss is so determined that it will displace just as much water, as to weight, as will balance the weight of all the parts which are fixed to the spindle, so as to reduce friction to a minimum. Although the apparatus is covered with glass, it has to be filled, before using it, with pure water to establish similarity of pressure inside and outside. After every experiment the water is removed and the spindle thoroughly dried.”
This example is marked “Elliott Bros. London.” The U.S. Geological Survey transferred it to the Smithsonian in 1916.
William Elliott began in business in London in the early 1800s, making and selling mathematical instruments. Following his death in 1853, his sons, Frederick and Charles, began trading as Elliott Brothers, and were soon offering a wide range of instruments for engineering and industry. The Elliotts’ involvement with water current meters probably began in 1856 when they acquired Watkins & Hill, a London firm that made meters according to the designs introduced by Joseph Saxton in 1836. Elliott Brothers was absorbed into what became BAE Systems in 1988. Its archives are now in the Museum of the History of Science in Oxford.
Ref: J. J. Révy, Hydraulics of Great Rivers (London and New York, 1874), appendix, “The Improved Current Meter, and Its Applications.”
Catalogue of the Special Loan Collection of Scientific Apparatus (London, 1876), p. 77.
Arthur H. Frazier, Water Current Meters in the Smithsonian Collections of the National Museum of History and Technology (Washington, D.C., 1974), pp. 50-51.
Location
Currently not on view
date made
1874-1916
maker
Elliott Brothers
ID Number
PH.289646
accession number
59263
catalog number
289646

Marvin Water Stage Register (Transmitter)

This is the transmitter for an instrument that was introduced in 1904 by Charles F. Marvin, a physicist who joined the federal weather service in the early 1880s, and rose to become Chief of the Weather Bureau.
Description
This is the transmitter for an instrument that was introduced in 1904 by Charles F. Marvin, a physicist who joined the federal weather service in the early 1880s, and rose to become Chief of the Weather Bureau. That organization transferred it to the Smithsonian in 1954, noting that it had been used at Columbus, Ohio. The clock movement is marked “SETH THOMAS.”
Ref: Roy Norton Covert, Instructions for the Installation and Maintenance of Marvin Water-Stage Registers (Washington, D.C., 1921).
Location
Currently not on view
maker
Seth Thomas Clock Co.
ID Number
PH.314524
accession number
204612
catalog number
314524

Surveyor's Vernier Compass

This is an incomplete example (the arms are missing) of an unusual 4–armed instrument. The needle rim is graduated to 30 minutes. The variation scale, at south, extends ± 20 degrees, and is read by vernier to single minutes. The “F.
Description
This is an incomplete example (the arms are missing) of an unusual 4–armed instrument. The needle rim is graduated to 30 minutes. The variation scale, at south, extends ± 20 degrees, and is read by vernier to single minutes. The “F. Arnold & Co.” inscription refers to Francis Arnold, an immigrant from Frankfurt, Germany, who signed naturalization papers in Philadelphia in 1854. After working briefly for William J. Young, Arnold went into business on his own, advertising as a manufacturer of surveying and engineering instruments. He settled in Chicago around 1860. By 1875, B. Kratzenstein was advertising as Successor to F. Arnold & Co.
Location
Currently not on view
date made
1850-1875
maker
F. Arnold & Co.
ID Number
PH.335531
catalog number
335531
accession number
321714

Railroad Compass

W. & L. E. Gurley introduced this type of instrument--a railroad compass with one vernier on the limb--in 1868. This example has a hand-engraved signature, and so was made before the middle of 1876, when Gurley’s engraving machine was up and running.
Description
W. & L. E. Gurley introduced this type of instrument--a railroad compass with one vernier on the limb--in 1868. This example has a hand-engraved signature, and so was made before the middle of 1876, when Gurley’s engraving machine was up and running. The upper plate carries the sights, two level vials, and the compass. The lower plate, wider than the upper, carries the circle, which is graduated to 30 minutes and read by vernier to single minutes. A tangent screw on the south arm moves the two plates relative to one another. A variation arc on the compass face extends 30 degrees either way. The folded vernier is moved by a rack and pinion located on the north arm, and reads to 2 minutes. The compass has a blackened or bronzed finish, and a silver–plated face. New, it cost $65.
The "Fagg & Bowe 1870" signature scratched on the inside of this compass refers to George S. Fagg and Archibald H. Bowe, who began working for Gurley in 1866. The "Edward Meister Baltimore 1872" signature refers to an independent instrument maker in Baltimore, Md. The "Geo. Shilling 1904 Wash. D.C." signature refers to an independent instrument maker in Washington, D.C. The "J. Heim 1885" signature has not been identified.
Ref: W. & L. E. Gurley, A Manual of the Principal Instruments Used in American Engineering and Surveying (Troy, N. Y., 1868), pp. 52–56.
W. Skerritt, "W. & L. E. Gurley's Engraving Machine," Rittenhouse 11 (1997): 97–100.
Location
Currently not on view
maker
W. & L. E. Gurley
ID Number
PH.330532
catalog number
330532
accession number
293490

Surveyor's Vernier Compass

This compass marked "Wm. J. Young Maker Philadelphia" has two notable features. One is that the variation arc and vernier mechanism are located on the compass face, under glass and protected from harm. A similar design appears in the drawing accompanying William J.
Description
This compass marked "Wm. J. Young Maker Philadelphia" has two notable features. One is that the variation arc and vernier mechanism are located on the compass face, under glass and protected from harm. A similar design appears in the drawing accompanying William J. Young's 1830 patent application for an "Improved Surveying Compass." That instrument, however, had a full divided circle rather than a small variation arc. The other feature of this compass--a dark face and a silvered needle ring--was also described in Young's patent, and seems to be found on all Young compasses with a needle 5 inches or longer. The Journal of the Franklin Institute 10 (1832): 34, explained that this improvement of Young's "consists in colouring the surface of the compass plate green, or bronzing it, instead of silvering it in the usual way, thereby relieving the eye from the unpleasant and injurious effects of the white plate. A narrow silvered rim surrounds the bronzed surface, giving a distinct view of the needle point."
This compass dates from the late 1840s or early 1850s, after the expiration of Young's patent and before Young began placing serial numbers on his instruments. The variation arc extends 20 some degrees either way, and is graduated to 30 minutes. The vernier is moved by rack and pinion located on the south arm and hidden under a brass plate, and reads to single minutes. There is an outkeeper and a level vial (now missing) on the north arm.
Ref: D. J. Warner, "William J. Young. From Craft to Industry in a Skilled Trade," Pennsylvania History 52 (1985): 53-68.
Location
Currently not on view
maker
Young, William J.
ID Number
1982.0104.03
accession number
1982.0104
catalog number
1982.0104.03

Maximum and Minimum Kiosk Thermometer

Like the thermometer introduced by James Six in England in 1782, this example has a U-shaped glass tube filled with alcohol and mercury. The tube has a milk-white back, and reads from -40 to +110 Fahrenheit on either side.
Description
Like the thermometer introduced by James Six in England in 1782, this example has a U-shaped glass tube filled with alcohol and mercury. The tube has a milk-white back, and reads from -40 to +110 Fahrenheit on either side. Its two ends are bent at right angles so that their cylindrical bulbs protrude out the back of the supporting black metal plate. This plate is marked, at top, “U.S. / WEATHER BUREAU / No 32” and in the middle “Taylor Instrument Companies / ROCHESTER, N.Y.” It is also marked “Tycos” with a flag announcing the company logo, “ACCURATUS TB.”
The Weather Bureau began building kiosks in 1909, equipping them with meteorological instruments, and placing them around the country where they would be seen by citizens. This thermometer was designed for that purpose, and probably was not available commercially .
Location
Currently not on view
date made
ca 1910
maker
Taylor Instrument Co.
ID Number
PH.314533
catalog number
314533
accession number
204612

Lowe's Psychrometer

Nathaniel M. Lowe, the manufacturer of Edson's Hygrodeik, patented a similar but somewhat simpler instrument for showing relative humidity. In this example, the chart is marked "LOWE'S Graphic Hygrometer or Hygrodeik" and "N. M.
Description
Nathaniel M. Lowe, the manufacturer of Edson's Hygrodeik, patented a similar but somewhat simpler instrument for showing relative humidity. In this example, the chart is marked "LOWE'S Graphic Hygrometer or Hygrodeik" and "N. M. LOWE, BOSTON, Mass." and "Patented April 9, 1878."
Ref: N. M. Lowe, "Psychrometers," U.S. Patent 202276 (1878).
Location
Currently not on view
date made
late 19th century
maker
Lowe, Nathaniel M.
ID Number
PH.325390
catalog number
325390
accession number
254284

E. and G. W. Bartholomew Shelf Clock, about 1820

Made by E. and G. W. Bartholomew in Bristol, Conn., about 1820, this clock features a thirty-hour wooden movement that strikes the hours.
Description
Made by E. and G. W. Bartholomew in Bristol, Conn., about 1820, this clock features a thirty-hour wooden movement that strikes the hours. The white-painted dial has Roman hour numerals, painted spandrels in gold and a central stylized ring of gold-painted designs inside the ring of hours. The mahogany case has a carved eagle splat, two hollow columns through which the weights fall, paw feet and three central parts: a clear glass door covers the dial, the center features a mirror and the bottom glass panel shows a reverse-painted scene with a structure and a tree inside a gold-leaf rectangle. Two weights and a brass-covered pendulum bob also survive. Inside the case, a printed label reads: "Patent Clocks Manufactured & Sold by E. & G. Bartholomew, Bristol, Conn. P. Canfield, Printer, Hartford.”
George Wells Bartholomew and his cousin Eli started a clockmaking business in Bristol, Conn., in 1828, and, when the partnership dissolved in a few short years, G. W. continued alone until 1840. He then opened a cutlery business, but abandoned it in 1848 to head to the California gold fields.
Reference:
Smith, Eddy N. et al., Bristol, Connecticut: “in the Olden Time New Cambridge,” which includes Forestville. Hartford, Conn.: City Printing, 1907.
Location
Currently not on view
date made
ca 1830
manufacturer
E. & G. Bartholomew
ID Number
ME.317039
catalog number
317039
accession number
233061

Surveyor's Vernier Compass

This compass is marked "T. R. RANDOLPH CINCINNATI. O." and "1234" and "PATENTED JUNE 24 '79." On June 24, 1879, Theodore F.
Description
This compass is marked "T. R. RANDOLPH CINCINNATI. O." and "1234" and "PATENTED JUNE 24 '79." On June 24, 1879, Theodore F. Randolph received a patent (#216,759) for a surveyor's compass with a telescope sight, in which the telescope and its supports can be detached from the compass. In this example (which is missing the telescope and its supports) the raised rim is silvered, and graduated to 30 minutes. The variation arc, which is located on the compass face, extends 25 degrees either way, and reads by double vernier to single minutes. The carrying case is marked "PATENTED NOV. 9, 1880," referring to Randolphs' patent (#234,331) for a seamless leather container of this sort. This instrument belonged to the University of Missouri at Columbia.
Ref: T. F. Randolph, Illustrated Catalogue and Price List (Cincinnati, 1892), p. 2.
Location
Currently not on view
maker
Randolph, Theodore F.
ID Number
PH.333647
catalog number
333647
accession number
300659

Wye Level

This level, which dates from the period 1875–1890 when F. Brandis & Co. was trading as such, is similar to the "18 Inch Patented Improved Wye Level as Made for U.S. Engineer Corps" that Brandis advertised in 1881, and that cost $140.
Description
This level, which dates from the period 1875–1890 when F. Brandis & Co. was trading as such, is similar to the "18 Inch Patented Improved Wye Level as Made for U.S. Engineer Corps" that Brandis advertised in 1881, and that cost $140. The patent in question (#201,155), granted to Brandis on March 12, 1878, described a spindle attachment that connects the telescopic level to the leveling head. The compass on this example is marked "F. BRANDIS & CO., NEW YORK 531." A label in the box dates from the period 1878–1879 when Brandis was in business with Richard Teckritz. It reads: "BRANDIS & TECKRITZ, MAKE in the most accurate manner, ALL KINDS OF MATHEMATICAL & ASTRONOMICAL INSTRUMENTS. Theodolites, Transits, Leveling Instruments, Sextants, Quadrants, Etc. Etc. All kinds of Instruments re–divided, re–paired and adjusted. No. 55 FULTON ST. NEW YORK."
Ref: F. E. Brandis, Illustrated and Descriptive Catalogue of Instruments of Precision for Field and Astronomical Purposes (New York, 1881), p.38.
Location
Currently not on view
maker
F. Brandis & Co.
ID Number
PH.337013
accession number
1979.0214
catalog number
337013

Surveyor's Transit

The inscription on this transit reads "Stackpole & Brother New York 655." The original bill of sale shows that John Ferris, a surveyor of Dutchess County, N. Y., bought this instrument from the Stackpoles in 1866.
Description
The inscription on this transit reads "Stackpole & Brother New York 655." The original bill of sale shows that John Ferris, a surveyor of Dutchess County, N. Y., bought this instrument from the Stackpoles in 1866. The basic trabsut cost $250, while the meridian finder--marked "Stackpole's Mern. Findr. Patented, Sep. 26, 1865 107"--cost an additional $40. William Stackpole's patent (#50,182) describes a small reflector that attaches to the objective end of the telescope, and that enables a surveyor to easily use the sun to locate the true meridian.
Ref: Conrad S. Ham, "A Family History of a Group of Surveying Instruments, 1750 to the Present Year 1954," Annual Report of Proceedings of the Connecticut Society of Civil Engineers 70 (1954): 134-138.
Location
Currently not on view
owner
Ferris, John
maker
Stackpole and Brother
ID Number
1983.0548.06
maker number
655
accession number
1983.0548
catalog number
1983.0548.06

Water Current Meter

This is a direct-reading instrument with a vertical axis and a five-bucket rotor that was said to be particularly suited for use in “the rough torrents, filled with drift of all sorts” found in Western waters.
Description
This is a direct-reading instrument with a vertical axis and a five-bucket rotor that was said to be particularly suited for use in “the rough torrents, filled with drift of all sorts” found in Western waters. Known variously as a Bailey or a Colorado water current meter, it was designed in the late 1880s by Howard Safford Bailey, a draughtsman who worked for the Western Mathematical Instrument Co. in Denver. It resembles the form developed in the early 1880s by Edwin Nettleton, the State Engineer of Colorado.
The U.S. Irrigation Survey, a project of the U.S. Geological Survey, used several meters of this sort. The Geological Survey transferred this example to the Smithsonian in 1908. The frame is nickel-plated.
Ref: J. W. Powell, “Irrigation Survey—Second Annual Report,” in Report of the Secretary of the Interior (Washington, D.C., 1890), vol. 4, part 2, pp. 6-8.
Arthur H. Frazier, Water Current Meters in the Smithsonian Collections of the National Museum of History and Technology (Washington, D.C., 1974), pp. 75-78.
Arthur H. Frazier and Wilbur Heckler, Embudo, New Mexico, Birthplace of Systematic Stream Gauging (Washington, D.C., 1972).
Location
Currently not on view
date made
ca 1890
ID Number
PH.248696
accession number
48341
catalog number
248696

Liquid Compass

This compass has a black metal bowl gimbal mounted in a mahogany box. The inscriptions read "DEAD BEAT" "C.B. PATENT" "No 11904" "HUSUN," and H. HUGHES & SON, LTD LONDON, PATD GT BRIT.
Description
This compass has a black metal bowl gimbal mounted in a mahogany box. The inscriptions read "DEAD BEAT" "C.B. PATENT" "No 11904" "HUSUN," and H. HUGHES & SON, LTD LONDON, PATD GT BRIT. No 127135."
Hughes trade literature describes this form as having been "especially designed for the navigation of Yachts and Motor Craft, the rapid movements of which demand a compass of exceptional steadiness and sensitivity." To that end, it has a special expansion chamber that "precludes the formation of bubbles in the liquid." The needles are short, and made of cobalt-steel. The card is printed "by a new photographic process that eliminates discoloration." And patented damping filaments ensure the steadiness of the card.
British Patent #127,135 describes an "Aperiodic Magnetic Compass" made by attaching to the magnetic needle filaments of glass, wire, or other suitable non-magnetic material. This patent was granted in 1919 to George Campbell and Geoffrey Bennett, both of the Compass Department of the British Admiralty.
H. Hughes & Son, Ltd. was in business, as such, from 1903 to 1947.
Ref: Henry Hughes & Son, Ltd., Husun "Dead-Beat" Compasses for Yachts (London, 1939).
H. L. Hitchins and W. E. May, From Lodestone to Gyro-Compass (New York, 1953), pp.150-152.
Location
Currently not on view
date made
1919-1947
maker
H. Hughes & Son, Ltd.
ID Number
PH.337074
accession number
1979.0026
catalog number
337074

Bath Thermometer

This glass thermometer has a red liquid (probably alcohol), a cylindrical bulb, and a bend in the tube above the bulb.
Description
This glass thermometer has a red liquid (probably alcohol), a cylindrical bulb, and a bend in the tube above the bulb. A paper marked “Thermomètre de Bains” carries a scale that extends from -35 to +80 Réaumur graduated in degrees, with indications for such things as “Eau Bou” (boiling water) and the coldest temperature at Paris in 1740, 1777, and 1788. The whole is encased in a glass tube.
Location
Currently not on view
date made
late 18th century
ID Number
PH.316458
catalog number
316458
accession number
223721

Rolling Navigation Ruler, 19th century

This brass rolling ruler is engraved with measurements on all four sides. There are rollers on either side of the ruler, connected by an axle. The object is well worn with a dent on one corner, and it is screwed together.
Description
This brass rolling ruler is engraved with measurements on all four sides. There are rollers on either side of the ruler, connected by an axle. The object is well worn with a dent on one corner, and it is screwed together. There are inches on one side of the ruler, on the remaining three sides the hash marks are slanted in ascending and descending increments of ten towards the center of the ruler ending in 90 making degree angles. The names “Cary London” and “R.F. Crawford R.N.” are stamped on the tool. William Cary was an instrument maker in London in the late 19th and early 20th centuries. “R.F. Crawford” was the owner of the instrument; the “R.N.” represents Royal Navy.
This navigational instrument was used to plot courses on nautical charts and could be rolled across a chart without changing its orientation. The different sides were used for angle or scale corrections on the meridians or curved lines on a globe connecting the poles.
Location
Currently not on view
ID Number
TR.320635
catalog number
320635
accession number
242721

Aneroid Barometer

This is a brass instrument, 4¾ inches diameter and 1¾ inches deep. The white face is marked “Aneroid Barometer” and “1634” and “STORMY Much Rain Rain CHANGE Fair Set Fair VERY DRY.” The pressure scale extends from 22.5 to 31.5 inches of mercury, read to twentieths of an inch.
Description
This is a brass instrument, 4¾ inches diameter and 1¾ inches deep. The white face is marked “Aneroid Barometer” and “1634” and “STORMY Much Rain Rain CHANGE Fair Set Fair VERY DRY.” The pressure scale extends from 22.5 to 31.5 inches of mercury, read to twentieths of an inch. There are two pointers so that one can determine if the pressure is rising or falling.
The U.S. Weather Bureau transferred this to the Smithsonian in 1954.
Location
Currently not on view
ID Number
PH.314548
accession number
204612
catalog number
314548

Desk Set

In this apparatus which came to the Smithsonian in 1923, a walnut base holds two circular instruments, each 3¼ inches diameter and 1½ inches deep. One is a clock. The other is an aneroid barometer with two pointers.
Description
In this apparatus which came to the Smithsonian in 1923, a walnut base holds two circular instruments, each 3¼ inches diameter and 1½ inches deep. One is a clock. The other is an aneroid barometer with two pointers. The pressure scale on the barometer extends from 27 to 31 inches of mercury, read to tenths of an inch. It is also marked “STORMY MUCH RAIN RAIN CHANGE FAIR SET FAIR VERY DRY.” A wooden pillar between these two instruments holds a mercury-in-glass thermometer with an enameled back and a metal plate with temperature scale.
Location
Currently not on view
date made
ca 1900
ID Number
PH.307962
accession number
69572
catalog number
307962

Wye Level

This wye level was made by Edmund Draper in Philadelphia, around 1870. The inscriptions read "E. Draper. Philad" and "294."Currently not on view
Description
This wye level was made by Edmund Draper in Philadelphia, around 1870. The inscriptions read "E. Draper. Philad" and "294."
Location
Currently not on view
maker
Draper, Edmund
ID Number
PH.337021
accession number
1977.1101
catalog number
337021

Surveyor's Vernier Compass

This surveyor's vernier compass has an unusual and ornate face decorated with Masonic symbols. The variation arc on the north arm extends 10 degrees either way; the vernier is moved by rack and pinion, and reads to 10 minutes. A level vial is on the south arm. The "J.
Description
This surveyor's vernier compass has an unusual and ornate face decorated with Masonic symbols. The variation arc on the north arm extends 10 degrees either way; the vernier is moved by rack and pinion, and reads to 10 minutes. A level vial is on the south arm. The "J. SIMPSON BARDSTOWN KY" inscription refers to Jonathan Simpson (1787-1863) who was was working in Kentucky by 1820, and who advertised in the Bardstown newspaper, The Republican, on October 3, 1844: "I shall keep on hand a constant supply of SILVERWORK of my own manufacture-warranted to be as good as any manufactured in the United States, and at the Cincinnati prices. My necessities compel me to labour as much as ever I did. I have a few Surveying instruments on hand, which I will sell very low."
Location
Currently not on view
maker
Simpson, Jonathan
ID Number
PH.325686
catalog number
325686
accession number
257690

Quartz Clock

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

Zenith Telescope

Marked "Troughton & Simms, London, 1849" and "U. S. C. S. Z. T. No. 4,” this is the last of four zenith telescopes that Troughton & Simms made for the U. S. Coast Survey.
Description
Marked "Troughton & Simms, London, 1849" and "U. S. C. S. Z. T. No. 4,” this is the last of four zenith telescopes that Troughton & Simms made for the U. S. Coast Survey. It arrived in the United States in 1849, and was used for the determination of latitude by the Talcott method. .
When the Survey agreed join in the variation of latitude (polar motion) program organized by the International Geodetic Association, and found that no other instruments were available, it decided to have zenith telescopes No. 2 and No. 4 "remodeled at the Survey Office." Edwin Smith, chief of the Instrument Division, explained that "every precaution" was taken to make these instruments "as perfect as possible under the circumstances." The new features included: base and leveling screws; vertical axis; wyes for horizontal axis of telescope, with adjustment for level; larger horizontal axis for the telescope; new micrometer screw and reconstruction of micrometer box and slide; improved clamp to telescope; two fine levels attached to telescope; and a striding level for the telescope axis. The whole instrument was polished and bronzed, and provided with electric lamps and batteries "for illumination of telescope field, the reading of levels, etc." Zenith telescope No. 2 was used in Hawaii in 1891–1892, while zenith telescope No. 4 was used at Rockville, Md.
Ref: [E. Smith], "On the Variation of Latitude at Rockville, Md., as Determined from Observations Made in 1891 and 1892 in Cooperation with the International Geodetic Association," United States Coast and Geodetic Survey Report for 1892, Appendix No. 1, pp. 4–5, with illustration.
Location
Currently not on view
maker
Troughton and Simms
ID Number
PH.316660
catalog number
316660
accession number
226636

Engineer's Chain

F. W. Simms in England noted in 1836 that the recent construction of canals and railroads had led to the introduction of a chain in which each link and its associated rings was 12 inches long.
Description
F. W. Simms in England noted in 1836 that the recent construction of canals and railroads had led to the introduction of a chain in which each link and its associated rings was 12 inches long. Chains of this sort, measuring either 50 or 100 feet overall, were soon known as engineer's chains. This example was sold by Keuffel & Esser in New York. It has 100 links made of No. 12 steel, and brass handles and tallies. It measures 100 feet overall. The links and rings are brazed shut. There is a spring hook (snap) at 50 feet, so that the surveyor can separate the chain into two equal halves. New, it cost $11. The U. S. Geological Survey transferred it to the Smithsonian in 1907.
Ref: Keuffel & Esser, Catalogue (New York, 1906), p. 505.
F. W. Simms, A Treatise on the Principal Mathematical Instruments (Baltimore, 1836), p. 10.
Location
Currently not on view
maker
Keuffel & Esser Co.
ID Number
PH.247951
catalog number
247951
accession number
47736

Price Water Current Meter

William Gunn Price, an employee of the U.S. Engineer Department, designed an exceptionally robust and successful water current meter. This example is the instrument that Gunn, with the aid of four mechanics, built in 1882.
Description
William Gunn Price, an employee of the U.S. Engineer Department, designed an exceptionally robust and successful water current meter. This example is the instrument that Gunn, with the aid of four mechanics, built in 1882. It has a five-conical bucket wheel mounted on a vertical-axis, and a four-blade rudder. It is 30.5 inches long. Gunn was living at Paducah, Ky., at that time, and used this meter on the Ohio and Mississippi Rivers. The U.S. Geological Survey transferred it to the Smithsonian in 1916.
Ref: Arthur H. Frazier, William Gunn Price and the Price Current Meters (Washington, D.C., 1967), p. 40.
Arthur H. Frazier, Water Current Meters in the Smithsonian Collections of the National Museum of History and Technology (Washington, D.C., 1974), pp. 78-87.
Location
Currently not on view
date made
ca 1882
ID Number
PH.289638
accession number
59263
catalog number
289638

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