Choose From Below   A History of Surveyors and Surveying   History of "Metes & Bounds" the Origin of the Mile, Foot, & Acre, Etc.     A History of Surveyors and Their Equipment Through the Ages   Surveyings Early Contributors of Particular Renown:   Galileo (Galilei) Leonard Digges (Nicolaus) Copernicus Leonardo da Vinci 1564 - 1642 1520 - 1559 1473 - 1543 1452 - 1519   Some of America's Early Surveyors:   Abraham Lincoln Henry David Thoreau Thomas Jefferson Daniel Boone George Washington James Cook 1809 - 1865 1817 - 1862 1743 - 1826 1734 - 1820 1732 - 1799 1728 - 1779   1778 CGS Thomas Jeffersons Theodolite Some of America's Renowned Survey teams:   (Meriwether) Lewis 1774 - 1809 & (William) Clark 1770 - 1838 (Charles) Mason 1728 - 1786 & (Jeremiah) Dixon 1733 - 1779 DEFINITION OF SURVEYING Surveying and Mapping: the measurement of distance, both horizontal and vertical, and measurement of direction, which determine the relative position of points above, on, or beneath the surface of the earth. It is a process of collecting information on positions and locations relative to known positions and locations on the earth's surface.   SURVEYING EQUIPMENT THROUGH THE AGES     MATHEMATICS, SURVEYING, AND CIVIL ENGINEERING Any work defining the history of surveying would be hard pressed to leave out those who contributed or helped define the mathematical and engineering sciences. Surveying required significant knowledge of mathematics, and Engineering required significant knowledge of both. States such as California have required that a portion of the civil engineering registration examination include a separate portion on surveying.     Engineers of the Millennium "CE News," the "voice" of civil engineering, saluted the engineers who shaped the future of civil engineering by portraying 10 persons who were selected as having contributed most to the profession in an article published in December of 1999. Historically, Da Vinci was the first of those; the next recipient was not even born until almost 200 years after the passing of Da Vinci. * Da Vinci is considered by many the ultimate renaissance man, skilled in the arts, mathematics, civil and military architecture, engineering, science, invention, and the design of weapons. He worked on lenses for a Telescope and provided a treatise on Perspective, both significant in the development of surveying. He was also a contemporary of Copernicus (1473-1543), and a precursor of Galileo (1564-1642).   *(For CE designates see http://www.graduatingengineer.com/articles/feature/12-20-99.html) The Telescope, Perspective, and Astronomy The Telescope has been the foundation of most modern survey equipment for hundreds of years. It is not known who made the first telescope, and in fact the first "eye lens" magnifiers are thought to have existed since the 13th Century, some 400 years before Galileo, in 1609, perfected the telescope such that it was useful in Astronomy. The making of the first Telescope is thought to have been about 200 years after the making of the eye-lens magnifier in the 13th Century. It is known that Leonardo Da Vinci was preparing lenses for a Telescope before 1520, and may have been the foundation for his belief that "all the universe would be made visible to the human eye." The Telescope has allowed the science of surveying to expand well beyond the range of ordinary vision, to include the extensive use of high altitude aircraft using photogrammetry to provide a significant amount of information for design and construction on many of the rural roadway systems in the world.   Not many realize how important the relative position of stars and planets were to surveyors and explorers up through the end of the 20th Century. But, interestingly, seafaring and frontier explorers could never have traveled without being able to "fix" on the stars after dark. Much like the "satellites" that now provide "global positioning" systems, astronomy played a major role in surveying for exact positioning up through the 1970's! Astronomers had predicted the existence and relative value of the "heliotropic" (earth turns about the sun) solar system many years before Copernicas. But Copernicas defined it and brought it into a viable theory using the more logical reasoning of his time (at or about the time of Da Vinci). The reasoning included the more valid use of correct positioning for surveying both the ocean and the vast land oasis's which followed the logical proper relation. However, it was not until Galileo was able to "perfect" the magnification of the Telescope in the early 1600's, that there was adequate confirmation of the theories of Copernicas in relation to the positioning of the planets and stars in the universe for it to be accepted, in spite of support from scholars such as Thomas Digges (see below under "Measuring Direction").   In 1508 Da Vinci explored visual angles in surveying under the heading of perspective. An interplay between surveying and perspective thus helps to account for the origins of an instrument called the proportional compass (cf. Galileo). There were close links between surveying and linear perspective. In Germany, it was assumed that the term "perspective" was synonymous with the "art of measurement." This perspective measurement of "stadia" was directly related to perspective and the telescope. The telescope allowed for lines to be projected onto the "target" some distance away when focusing on it which, when combined with the distance subtended by the lines, provided a means of calculating the distance to the target.   Most 20 Century leveling instruments had "stadia" lines, one above and one below the "crosshairs" in the "perspective," one each above and below the leveled center of the view in the scope. A constant was provided for the magnification of the particular instrument's scope, which, when used, could be multiplied by the measurement on the vertical target rod seen between the top and bottom cross hairs to determine the distance to the target.   Cyclopedia, 1728     MEASURING DISTANCES (RANGE)       Trundle Wheel, Perambulator, and Odometer     For early surveying work the perambulator was used to measure distances. It was a device that had a wheel that was pushed along a linear path while the number of revolutions of the wheel was counted either manually or by an odometer attached to the frame. Depending on the radius of the wheel, distance could then be determined by calculating circumference times the number of revolutions. Trundle wheels, which work in the same manner, usually measure a standard one meter per revolution.       Chain     Chaining was a common method of measuring land boundaries. The chain was usually made of steel and has various numbers of links. In some of the more common chains, each link was 7.92 inches long, and each chain of 100 links was 66 feet long. (7.92" × 100 = 792 inches. 792 ÷ 12 = 66 feet.) That meant there were 20 chain lengths in a ¼ mile, 40 chain lengths in a ½ mile and 80 chain lengths in every one-mile section (which is a quarter, a half and a full section of land, respectively). Chains are not used today, and only a few remain although many existed at one time.       Tapes     Taping is the most common method of measuring distances. Accurate surveyors' tapes made of steel or a steel alloy with a typical length of 100 feet or 100 meters were used for surveying distances other than land boundaries more and more until the 20th Century, when "chains" began to disappear due to the decrease in land boundary use. For very accurate measurements, the temperature of the tape must be taken into account, as well as the tension of the "pull." Each Steel Tape had its own "temperature" and "tension" coefficient, which was used to correct each measurement. Non-metallic tapes are now common that are woven from synthetic yarns with or without metallic threads. The steel "tape" on a reel, commonly used until electronic measuring became widespread, was still often referred to as a "chain."       Stadia     A stadia is a graduated measuring rod that is held vertically at a location whose distance is required to be known. The rod is sighted through the optical equipment (transit, theodolite, alidade, telescope) and the distance read on the stadia rod is in proportion to the distance from the equipment to the rod.   MEASURING DIRECTION (BEARING, ANGLE, AZIMUTH)       Topographical Instrument     This drawing, thought to depict a precursor to the "Theodolite," the "Transit," and the "Altitude/Azimuth" instrument of the same genre, came from the Thomas Digges' "Pantometria" published in 1571, which he credited mostly to his late father, Leonard Digges. Note that this was, as many instruments were and still are today, produced as a war defense mechanism. Leonard Digges, Thomas' Father, an Englishman, was a well-known mathematician and surveyor, who was credited by many with the inventions of the theodolite and telescope, and was himself a popular man of science through his many other publications in English. Digges' son, Thomas, was a pivotal player in popularization of the "Heliotropic" theories of Copernicus contained in Copernicus' book "De revolutionibus orbium coelestium."       Leonard Digges is also sometimes credited with independently inventing the reflecting and even the refracting Telescopes, which cannot be denied considering the number of claims that were lodged when Galileo laid claim to the invention in 1608-09. Galileo is still credited with perfecting the Telescope to provide a magnification of 10-20 times as compared to the approximate 3 fold magnification available prior to that, which made it sufficient for Astronomical observations and further verification of the Heliotropic theory of Copenicus.       Compasses     These are devices that usually measure an angle using a known deviation, such as a deviation from Magnetic or True North.       Alidade       This instrument consists of a telescope mounted on a column attached to a platform. The telescope could be rotated vertically and horizontally. The instrument could be used for leveling and for plane table surveying. Simple alidades can be made using a ruler (or straight length of wood) with a nail positioned vertically at each end. By placing the ruler flat on the plane table, sightings can be made by aligning the nails.       Plane table     A plane table is a portable drawing board mounted on a tripod or stand. It consists of an alidade, board and the tripod or stand. The locations of lines and points are plotted directly on the drawing paper. Setting up the table requires care to ensure that it is level and that it is oriented correctly with a reference meridian (e.g. north line). The table is moved and re-oriented at each station along the survey route. Plane table mapping is rarely used in the current world of electronic surveying, but for an excellent tutorial on the use of a very simple Plane Table, visit: www.scouting.org.za [PDF] 38.7KB     Transit         This is an angle-measuring device based on a telescope with the capability of being able to turn in all directions while supported by a stable tripod. This ability allows the "barrel" of the transit to be "flopped" over and then when re-sighting the original point, the angle should then read exactly 180 degrees from the first measured angle. This "checking" advantage allows you to be assured the instrument is properly calibrated. Transits have been used since the early 19th century.     Theodolite         A Theodolite is a more sophisticated version of a transit. The Theodolite is the principal instrument used in the measurement of angles in triangulation. The first description of a theodolite, or 'theodelitus', is found in the surveying textbook "Pantometria" (1571) by Thomas Digges (son of Leonard Digges, who is widely credited with the invention). The elder Digges also conceived the name, but its origin is unclear.   MEASURING ELEVATIONS     Wye Level       Jonathan Sisson introduced this instrument in London in the 1720s. The "Wye" Level was the standard bearer of leveling instruments for many years prior to the introduction of Electronic Distance Measuring (EDM) instruments. It was called the "wye" because the scope or "barrel" of the telescope was clamped to two "Y" shaped platforms (which later became "C"s), one in front and one in back of the scope. The scope, the longest part of the instrument, could be removed for transport from project to project in earlier models which allowed for change of the scope if one needed to be calibrated.     Dumpy level         This is an instrument used primarily for leveling. It is able to measure the differences in elevation of observed features. Horizontal angles can also be measured and distances determined with the aid of a stadia rod. The term "dumpy level" originated from the dumpy appearance of some older models which had inverting eyepieces and relatively short telescopes. William Gravatt introduced the dumpy level in 1830. Its telescope is fixed in its supports. The dumpy level is less precise but more rugged than the Wye level. A dumpy level with a small horizontal circle is known as an architect's or builder's level.   FINDING DIRECTION, DISTANCES, AND ELEVATIONS WITH ELECTRONICS     Electronic Distance Measuring (EDM)     Geodimeters         Early attempts at "Electronic Distance Measuring" (or EDM's) were hampered by the gross weight and manual complexity of the controls. Those who initially designed the instrument were "lab electronics" engineers, and the resultant design was something that might be "indestructible" but almost unmanageable. The unit above, a "4D" model, is actually a considerable improvement over earlier models, which were too cumbersome to be carried over rough terrain. For lightwave or daylight instruments, accuracy of the measurements could be affected by optics alignment, frequency drift, and calibration curve errors in the phase readings. Altimeter readings were often taken to compensate for elevation. The 4D Geodimeter used a high-pressure mercury vapor lamp rather than a common tungsten light bulb as its light source. First manufactured in 1963, the "D" in its designation indicated that it could be used in daylight. The Coast and Geodetic Survey (C&GS) used this model throughout the 1960s. In 1966, the 4D was modified to use a laser as its light source, in order to increase its range in moderate haze and to measure longer distances in bright sunlight. C&GS technician George Lesley replaced the mercury vapor lamp with a three-milliwatt helium-neon gas laser. The modified 4D was designated "4L," and replaced the 2A and 4D models on the USGS Transcontinental Traverse. Later, the three-milliwatt laser was replaced with a six-milliwatt laser and the model was renamed "4L 6A."     Laser - Big Red         As a result of the technology developed by the U.S. Coast & Geodectic Survey and the organizations that supported them, AGA produced the first commercially available electronic distance measuring instrument with a laser light source, which it designated Model 8. These models were also used in Transcontinental Traverse observations and were known initially as "Big Red".     Lidar & Ladar   The "American Society for Testing and Materials," Committee E57* has recently completed Specification Designation E2544-07, which defines LADAR as "n. - laser detection and ranging system" and LIDAR as "n. - light detection and ranging system." A typical LIDAR system rapidly transmits pulses of light that reflect off the terrain and other objects. The return pulse is converted to electrical impulses and collected by a high-speed data recorder. Since the formula for the speed of light is well known, time intervals from transmission to collection are easily derived. Time intervals are then converted to distance based on positional information obtained from the instrument. A 3-D Imaging System is defined by the ASTM Designation E2544-07 as an optical instrument (within the infrared to ultraviolet wavelengths) that is used to rapidly measure (on the order of thousands of measurements per second or faster) the range and bearing to and/or the 3-D coordinates of points on an object or within an area of interest.         The Beetle was designed and produced by Precision International, a firm established in June 1971 by men who had worked at the Engineering Development Center at Arnold Air Force Base in Tullahoma, Tennessee. Precision International was bought by Wild Heerbrugg in 1979, and by Cubic Precision in 1984.           NATIONAL GEODETIC SURVEY (NGS)     NGS Electronic Leveling     As of 2006, a Leica DNA03 is the standard leveling instrument used by NGS.       The National Oceanic and Atmospheric Administration's (NOAA's) National Geodetic Survey (NGS) defines and manages a national coordinate system. This network, the National Spatial Reference System (NSRS), provides the foundation for transportation and communication; mapping and charting; and a multitude of scientific and engineering applications.     COAST & GEODETIC SURVEY CONTRIBUTION   The Coast & Geodetic Survey has been instrumental in providing for the development of surveying instruments since inception in the 1800's. Because they are charged with surveying the face of America, they were responsible for providing survey monuments for local surveyors throughout the country, requiring better and more efficient equipment to meet the challenge.     Early C&GS Theodolite     Prior to Electronic Measuring Devices, some of the early development included a three hundred pound, 30 inch horizontal circle theodolite made for the agency in 1836. The geodimeter gained rapid development in part because of the C&GS needs for bigger and better equipment. This enormous machine was destroyed by a tornado in November 1873.       Portions of this material were retrieved from: http://celebrating200years.noaa.gov/distance_tools/geodimeters http://celebrating200years.noaa.gov/foundations/leveling/welcome.html http://americanhistory.si.edu/collections/surveying/type.cfm?typeid=13       - Back to Top -