A plane table (plain table prior to 1830)[1] is a device used in surveying 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.[2]
The earliest mention of a plane table dates to 1551 in Abel Foullon's "Usage et description de l'holomètre", published in Paris.[3] However, since Foullon's description was of a complete, fully developed instrument, it must have been invented earlier.[2]
A brief description was also added to the 1591 edition of Digge's Pantometria.[3] The first mention of the device in English was by Cyprian Lucar in 1590.[1]
Some have credited Johann Richter, also known as Johannes Praetorius,[4] a Nuremberg mathematician, in 1610[5] with the first plane table, but this appears to be incorrect.
The plane table became a popular instrument for surveying.[2] Its use was widely taught. Some considered it a substandard instrument compared to other devices such as the theodolite, since it was relatively easy to use.[1] 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 in spatial and temporal surveying.(Lokendra prashad Bhatta)
Construction
A plane table with part of the surface cut away to show the mounting on the tripod. The mount allows the table to be levelled. On the table, the alidade with telescopic sight is seen.
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 levels, 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 is used to sight objects of interest. The alidade, in modern examples of the instrument a rule with a telescopic sight, 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 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 marks in the telescope of the alidade.
^ abcKiely, Edmond, Surveying Instruments: Their history and classroom use, Bureau of Publications, Teachers College, Columbia University, 1947. page 228
^ abTurner, Anthony, Early Scientific Instruments, Europe 1400-1800, Sotheby's Publishing, 1987, ISBN0-85667-319-6. page 81
^Vai, Gian Battista, Caldwell, W. G. E. The Origins of Geology in Italy Google books online copy
^Laussedat, Amié, Recherches sur les instruments, les méthodes et le dessin topographiques, Paris, 1898-1902, two volumes
Raymond Davis, Francis Foote, Joe Kelly, Surveying, Theory and Practice, McGraw-Hill Book Company, 1966 LC 64-66263
External links
in the collection of the Smithsonian National Museum of American History. This image shows the bubble levels on the base.
plane, table, mountain, plane, table, plane, table, plain, table, prior, 1830, device, used, surveying, site, mapping, exploration, mapping, coastal, navigation, mapping, related, disciplines, provide, solid, level, surface, which, make, field, drawings, chart. For the mountain see Plane Table A plane table plain table prior to 1830 1 is a device used in surveying 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 2 Contents 1 History 2 Construction 3 Usage 4 References 5 External linksHistory Edit Using a plane table The earliest mention of a plane table dates to 1551 in Abel Foullon s Usage et description de l holometre published in Paris 3 However since Foullon s description was of a complete fully developed instrument it must have been invented earlier 2 A brief description was also added to the 1591 edition of Digge s Pantometria 3 The first mention of the device in English was by Cyprian Lucar in 1590 1 Some have credited Johann Richter also known as Johannes Praetorius 4 a Nuremberg mathematician in 1610 5 with the first plane table but this appears to be incorrect The plane table became a popular instrument for surveying 2 Its use was widely taught Some considered it a substandard instrument compared to other devices such as the theodolite since it was relatively easy to use 1 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 in spatial and temporal surveying Lokendra prashad Bhatta Construction Edit A plane table with part of the surface cut away to show the mounting on the tripod The mount allows the table to be levelled On the table the alidade with telescopic sight is seen 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 levels 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 EditIn 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 is used to sight objects of interest The alidade in modern examples of the instrument a rule with a telescopic sight 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 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 marks in the telescope of the alidade References Edit a b c Turner Gerard L E Scientific Instruments 1500 1900 An Introduction University of California Press 1998 ISBN 0 85667 491 5 This is an updated version of his earlier Antique Scientific Instruments Blandford Press Ltd 1980 ISBN 0 7137 1068 3 a b c Kiely Edmond Surveying Instruments Their history and classroom use Bureau of Publications Teachers College Columbia University 1947 page 228 a b Turner Anthony Early Scientific Instruments Europe 1400 1800 Sotheby s Publishing 1987 ISBN 0 85667 319 6 page 81 Vai Gian Battista Caldwell W G E The Origins of Geology in Italy Google books online copy Laussedat Amie Recherches sur les instruments les methodes et le dessin topographiques Paris 1898 1902 two volumes Raymond Davis Francis Foote Joe Kelly Surveying Theory and Practice McGraw Hill Book Company 1966 LC 64 66263External links EditTelescopic Plane Table Alidade in the collection of the Smithsonian National Museum of American History This image shows the bubble levels on the base http www sciencemuseum org uk objects surveying 1933 7 aspx Retrieved from https en wikipedia org w index php title Plane table amp oldid 1127275407, wikipedia, wiki, book, books, library,
