Wild Heerbrugg described the Distomat DI3000 as "the fastest infra-red EDM with geodetic accuracy." With a laser diode light source, it had a range of 14 km. It was also relatively light (3.7 lb.), and could used in a yoke or fit onto any Wild optical or electronic theodolite. The National Imagery and Mapping Agency transferred this example to the Smithsonian in 2000.
Wild Heerbrugg described the Distomat DI5S as a small, compact, and highly accurate electronic distance measuring instrument. It had a range of up to 5 km with a 3mm + 2ppm standard deviation, and was designed to fit on any Wild theodolite in such a manner that it could be fully transiting. The DI5S was introduced in the mid-1980s. The National Imagery and Mapping Agency transferred this example to the Smithsonian in 2000.
This instrument, which the U. S. War Department transferred to the Smithsonian in 1933, was probably used by the Army Topographical Engineers.It is marked "Troughton & Simms, London 2" and was made perhaps as early as the 1840s. It has a double-cone horizontal axis, a lamp for illuminating this axis, a large striding level, a small vertical circle at one end of the horizontal axis, and an iron base.
A subtense bar is a bar of known length, with targets at either end. It is usually made of a stable material such as invar (an iron-nickel alloy). When used with a theodolite, it serves as a quick and convenient method of measuring distances indirectly. The subtense technique is similar to that involving a tachymeter and graduated rod. Subtense bars were in use in Europe by 1930. The inscription on this example reads "WILD HEERBRUGG SWITZERLAND No. 86845."
Ref: Wild Heerbrugg, Wild GBL 2m Subtense Bar (Heerbrugg, 1972).
F. Ackerl, "Entfernungsmessungen mit der Wildschen Invar-Basislatte," Zeitschrift für Instrumentenkunde 9 (1932): 393-400.
In 1620 an English mathematician named Edmund Gunter described a surveyor's chain with 100 links, measuring 66 feet (22 yards or 4 poles) overall. By this design, one square chain equals 484 square yards, ten square chains equal an acre, and eighty chains equal a mile. Building on this work, an English mathematician named Vincent Wing (1619-1668) introduced a 2 pole chain with 40 links. This example is of that sort. It is, moreover, associated with the vernier compass marked "F. Heiseley Fredk: town" in the Museum collection.
Carl Zeiss introduced the Model Ni 002 Automatic Geodetic Level around 1973, terming it a self-aligning level of maximum precision. This example is marked "AUS JENA Ni 002" and "456506" and "Made in German Democratic Republic." It belonged to the U. S. National Geodetic Survey. New, it cost $5,000. An additional tag reads "U.S. Government 48824 Dept. of Commerce NOAA."
Ref: Gerhard Hüther, "The new Automatic Geodetic Level Ni 002 of VEB Carl Zeiss JENA," Jena Review (Spring 1973): 56-60.
Carl Zeiss, Instruction ManualAutomatic Geodetic Level NI 002. .
This theodolite marked "WILD HEERBRUGG SWITZERLAND T2-50903" was probably made around 1956. It has its original airtight and watertight steel case, and its original wooden shipping case. The letters on the steel case-DMATC 17502-refer to the U. S. Defense Mapping Agency Topographic Center. The National Imagery and Mapping Agency, successor to DMA, transferred it to the Smithsonian in 2000.
Ref: Wild, Universal Theodolite Wild T2 Model 56 (Heerbrugg, 1956).
This somewhat unusual instrument has a micrometer screw at one end, to be used for fine adjustment, and its telescope has the same diameter from one end to the other. The “Bate London” inscription refers to Robert Brettell Bate, an instrument maker who was active during the first half of the 19th century.
The semicircle of this graphometer is graduated to 30 minutes, numbered clockwise and counterclockwise, and read by verniers at either end of the alidade to single minutes. There is no magnetic compass.
Range finder with a "STADIMETER U.S. NAVY BUREAU OF ORDNANCE MARK III MOD. 1 NO. 409 / 1918 INSPEC. CHD MADE BY KEUFFEL & ESSER CO. NEW YORK" inscriptions. Unlike the other examples in the collection, this one has a telescopic sight. It was made during World War I. The form was developed in the 1890s by the innovative American naval officer, Bradley Allen Fiske (1854-1942).
Ref: Instructions for the Use and Care of the Fiske Ship-Telegraphs and Stadimeter (Published by Authority of the Bureau of Ordnance, Navy Department, 1896).
Paolo E. Coletta, Admiral Bradley A. Fiske and the American Navy (Lawrence: University of Kansas Press, 1979), pp. 38-40.
This waywiser has a wooden frame and a dial of silvered brass with the usual scales, one for poles and furlongs and the other for miles. A small inset dial divided into 100 sections keeps a talley in terms of links of a chain. The "Heath & Wing LONDON" signature refers to Thomas Heath and Tycho Wing who worked together during the period 1751–1773.
Ref: Gloria Clifton, Directory of British Scientific Instrument Makers 1550–1851 (London, 1995), p. 131.
Zeiss brought out its first optical theodolite with graduated glass circles, the Th I, in 1924, and they produced the Th II, a one-second instrument of this sort, during the years 1935-1941. This example may be one of the many instruments that American intelligence officers captured from the German geodetic office at the end of World War II. The U. S. National Imagery and Mapping Agency transferred it to the Smithsonian in 2000.
The signature reads "Th II CARL ZEISS JENA Nr. 34390." A brass tag on the box reads "SICKLER KARLSRUCH.I.B.gegenuber der HAUPTPOST." The inscription painted on the box--"No. 45 AMS GEOD DIV"--refers to the Geodetic Division of the U. S. Army Map Service.
Ref: Carl Zeiss, Zeiss Repeating Theodolite II, Instructions for Use (Jena, 1936).
The inscription on this compass reads "Dietzgen Made in U.S.A." Dietzgen introduced the form in the 1930s, describing it as a Surveying and Timber Cruisers’ Compass of an "improved type as made by us for the U.S. Government." It was designed to make "the entrance of moisture or dust practically impossible." The needle ring is graduated to degrees, and numbered in quadrants from N and S. A pinion with capstan head, located outside the box at W and marked "Declination," is used to offset the compass for magnetic variation. The National Imagery and Mapping Agency transferred this example to the Smithsonian in 2000.
This alidade consists of a cherry bar with folding brass sights located near either end and centered on one beveled edge. The other beveled edge is graduated to quarter inches. The U.S. Geological Survey transferred it to the Smithsonian in 1907.
In 1620 an English mathematician and astronomer named Edmund Gunter described a surveyor's chain with 100 links, measuring 66 feet (22 yards or 4 poles) overall. By this design, one square chain equals 484 square yards, ten square chains equal an acre, and eighty chains equal a mile. Gunther's design proved extremely popular, especially in English lands. This example belonged to John Johnson (1771-1841), the Surveyor General of Vermont. It is made of steel, with round handles at either end, brass tallies every 10 links, and swivels every 25 links. Each link is joined to the next by three rings, and each unit (link and three rings) is 7.92 inches long.
This waywiser has a wooden frame, and a dial of silvered brass with the usual scales, one for poles and furlongs and the other for miles. The "J. Sisson LONDON" signature refers to Jonathan Sisson (c. 1690–1749) or his son, Jeremiah Sisson (1720–1783).
A waywiser consists of a large wheel that can roll along a level surface, and a dial that registers the distance traveled. The wheel usually measures 8.25 feet in circumference, such that 2 revolutions are equal to 1 pole. The larger hand on the dial makes one sweep per mile (320 poles or 8 furlongs). The shorter hand indicates the number of miles traveled. Waywisers became popular in England in the 18th century, and were still in use in the United States in the late 19th century. They were was also known as perambulators.
Ref: Jane Insley, "Odometer," in Robert Bud and Deborah Warner, eds., Instruments of Science (New York and London, 1998), pp.423–424.