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 land, terrestrial Plane (mathematics), two-dimensional or Three-dimensional space#In Euclidean geometry, three-dimensional positions of Point (geom ...

, 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. " Plane" refers to the table being both flat levelled ( horizontal).

History

The earliest mention of a plane table dates to 1551 in Abel Foullon's ''"Usage et description de l'holomètre"'', published in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

.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 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 (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...

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 ...

, 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 in conjunction with a phototheodolite, 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.

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). Two basic designs exist: ''tubular'' (or ''linear'') and '' bull's eye'' (or ''circular'' ...

s, in a

horizontal plane Horizontal may refer to: *Horizontal plane, in astronomy, geography, geometry and other sciences and contexts *Horizontal coordinate system, in astronomy *Horizontalism, in monetary circuit theory *Horizontalidad, Horizontalism, in sociology *Hor ...

. 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 Triangulation (surveying), tr ...

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

, 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 landforms 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 education science company that provides educational content, software, and services for students and educators across various levels—from K-12 to higher education and professional settings. They produce textbooks, ...

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

Table Table may refer to: * Table (database), how the table data arrangement is used within the databases * Table (furniture), a piece of furniture with a flat surface and one or more legs * Table (information), a data arrangement with rows and column ...

Tables (furniture)