A plane table (plain table prior to 1830) is a device used in

surveying Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is ca ...

site mapping, exploration mapping, coastal navigation mapping, and related disciplines to provide a solid and level surface on which to make field drawings, charts and maps. The early use of the name ''plain table'' reflected its simplicity and plainness rather than its flatness.

History

US Army Corps of Engineers Map Making, World War I

The earliest mention of a plane table dates to 1551 in

Abel Foullon Abel Foullon (1513–1563 or 1565, in France) was an author, director of the Mint (coin), Mint for Henry II of France and also an engineer to the king of France after Leonardo da Vinci. His Holometer is an instrument for making of angular mea ...

's ''"Usage et description de l'holomètre"'', published in

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...

.Turner, Anthony, ''Early Scientific Instruments, Europe 1400-1800'', Sotheby's Publishing, 1987, . page 81 However, since Foullon's description was of a complete, fully developed instrument, it must have been invented earlier. A brief description was also added to the 1591 edition of Digge's ''Pantometria''. The first mention of the device in English was by

Cyprian Lucar Cyprian Lucar (1544–1611) was an English mechanician and author. Life He was born in London in 1544. His grandfather was John Lucar of Bridgwater, Somerset. His father, Emanuel Lucar, was a member of the Merchant Taylors' Company. Career H ...

in 1590.Turner, Gerard L'E., ''Scientific Instruments 1500-1900, An Introduction'',

University of California Press The University of California Press, otherwise known as UC Press, is a publishing house associated with the University of California that engages in academic publishing. It was founded in 1893 to publish scholarly and scientific works by faculty ...

, 1998 . This is an updated version of his earlier ''Antique Scientific Instruments'' Blandford Press Ltd. 1980, Some have credited Johann Richter, also known as Johannes Praetorius, Vai, Gian Battista, Caldwell, W. G. E. ''The Origins of Geology in Italy''
Google books online copy a

Nuremberg Nuremberg ( ; german: link=no, Nürnberg ; in the local East Franconian dialect: ''Nämberch'' ) is the second-largest city of the German state of Bavaria after its capital Munich, and its 518,370 (2019) inhabitants make it the 14th-largest ...

mathematician, in 1610Laussedat, Amié, ''Recherches sur les instruments, les méthodes et le dessin topographiques'', Paris, 1898-1902, two volumes with the first plane table, but this appears to be incorrect. The plane table became a popular instrument for

.Kiely, Edmond, ''Surveying Instruments: Their history and classroom use'', Bureau of Publications, Teachers College, Columbia University, 1947. page 228 Its use was widely taught. Some considered it a substandard instrument compared to other devices such as the

theodolite A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and i ...

, since it was relatively easy to use. By allowing the use of graphical methods rather than mathematical calculations, it could be used by those with less education than other instruments. The addition of a camera to the plane table, as was done from 1890 by

Sebastian Finsterwalder Sebastian Finsterwalder (4 October 1862 – 4 December 1951) was a German mathematician and glaciologist. Acknowledged as the "father of glacier photogrammetry"; he pioneered the use of repeat photography as a temporal surveying instrument in mea ...

in conjunction with a

phototheodolite A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and i ...

, established

photogrammetry Photogrammetry is the science and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring and interpreting photographic images and patterns of electromagnetic radiant ima ...

in spatial and temporal surveying.(Lokendra prashad Bhatta)

Construction

A plane table consists of a smooth table surface mounted on a sturdy base. The connection between the table top and the base permits one to level the table precisely, using

bubble level A spirit level, bubble level, or simply a level, is an instrument designed to indicate whether a surface is horizontal (level) or vertical (plumb). Different types of spirit levels may be used by carpenters, stonemasons, bricklayers, ot ...

s, in a horizontal plane. The base, a tripod, is designed to support the table over a specific point on land. By adjusting the length of the legs, one can bring the table level regardless of the roughness of the terrain.

Usage

In use, a plane table is set over a point and brought to precise horizontal level. A drawing sheet is attached to the surface and an

alidade An alidade () (archaic forms include alhidade, alhidad, alidad) or a turning board is a device that allows one to sight a distant object and use the line of sight to perform a task. This task can be, for example, to triangulate a scale map on site ...

is used to sight objects of interest. The alidade, in modern examples of the instrument a

rule Rule or ruling may refer to: Education * Royal University of Law and Economics (RULE), a university in Cambodia Human activity * The exercise of political or personal control by someone with authority or power * Business rule, a rule perta ...

with a

telescopic sight A telescopic sight, commonly called a scope informally, is an optical sighting device based on a refracting telescope. It is equipped with some form of a referencing pattern – known as a ''reticle'' – mounted in a focally appropriate po ...

, can then be used to construct a line on the drawing that is in the direction of the object of interest. By using the alidade as a surveying level, information on the

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...

of the site can be directly recorded on the drawing as elevations. Distances to the objects can be measured directly or by the use of

stadia mark Stadia marks, also called stadia lines or stadia hairs, are crosshairs on the reticle of a theodolite or other surveying instrument that allow stadiametric rangefinding. Etymology The term stadia mark derives from the obsolete unit of distance, t ...

s in the telescope of the alidade.

References

{{reflist *Raymond Davis, Francis Foote, Joe Kelly, ''Surveying, Theory and Practice'',

McGraw-Hill McGraw Hill is an American educational publishing company and one of the "big three" educational publishers that publishes educational content, software, and services for pre-K through postgraduate education. The company also publishes referenc ...

Book Company, 1966 LC 64-66263

External links

Telescopic Plane Table Alidade
in the collection of the Smithsonian National Museum of American History. This image shows the

s on the base. * http://www.sciencemuseum.org.uk/objects/surveying/1933-7.aspx Measuring instruments Surveying instruments Historical scientific instruments