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Great Trigonometric Survey

A map by the survey, produced in 1870

The Great Trigonometric Surveywas a project of theSurvey of India throughout most of the19th century. It was piloted in its initial stages byWilliam Lambton,and later byGeorge Everest.

Among the many accomplishments of the Survey were the demarcation of theBritish territoriesinIndia and the measurement of the height of theHimalayan giants:Everest,K2,and

Kanchenjunga.The Survey had an enormous scientific impact as well, being responsible for one

of the first accurate measurements of a section of an arc oflongitude,and for measurements of

thegeodesic anomaly.

History [edit]

http://en.wikipedia.org/wiki/Survey_of_Indiahttp://en.wikipedia.org/wiki/William_Lambtonhttp://en.wikipedia.org/wiki/George_Everesthttp://en.wikipedia.org/wiki/United_Kingdom_of_Great_Britain_and_Irelandhttp://en.wikipedia.org/wiki/Indiahttp://en.wikipedia.org/wiki/Himalayahttp://en.wikipedia.org/wiki/Mount_Everesthttp://en.wikipedia.org/wiki/K2http://en.wikipedia.org/wiki/Kanchenjungahttp://en.wikipedia.org/wiki/Longitudehttp://en.wikipedia.org/wiki/Vertical_deflectionhttp://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=1http://en.wikipedia.org/wiki/File:1870_Index_Chart_to_GTS_India-1.jpghttp://en.wikipedia.org/wiki/File:1870_Index_Chart_to_GTS_India-1.jpghttp://en.wikipedia.org/wiki/File:1870_Index_Chart_to_GTS_India-1.jpghttp://en.wikipedia.org/wiki/File:1870_Index_Chart_to_GTS_India-1.jpghttp://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=1http://en.wikipedia.org/wiki/Vertical_deflectionhttp://en.wikipedia.org/wiki/Longitudehttp://en.wikipedia.org/wiki/Kanchenjungahttp://en.wikipedia.org/wiki/K2http://en.wikipedia.org/wiki/Mount_Everesthttp://en.wikipedia.org/wiki/Himalayahttp://en.wikipedia.org/wiki/Indiahttp://en.wikipedia.org/wiki/United_Kingdom_of_Great_Britain_and_Irelandhttp://en.wikipedia.org/wiki/George_Everesthttp://en.wikipedia.org/wiki/William_Lambtonhttp://en.wikipedia.org/wiki/Survey_of_India

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Colonel Thomas Tupper Carter-Campbell of Possil,a surveyor in the Great TrigonometricSurvey of the 3rd Grade.

The Great Trigonometrical Survey of India started on 10 April 1802 with the measurement of a

baseline nearMadras.Major Lambton selected the flat plains withSt. Thomas Mount at thenorth end and Perumbauk hill at the southern end. The baseline was 7.5 miles (12.1 km) long.

Lieutenant Kater was despatched to find high vantage points on the hills of the west so that the

coastal points ofTellicherry andCannanore could be connected. The high hills chosen were

Mount Delly andTadiandamol.The distance from coast to coast was 360 miles (580 km) andthis survey line was completed in 1806.

[1]TheEast India Company thought that this project

would take about 5 years but eventually it took more than 60 years, draining the profits of the

Company, so much so it was brought under the Crown after 1857.[citation needed

]Because of theextent of the land to be surveyed, the surveyors did nottriangulate the whole of India but instead

created triangulation chains running from North to South and East to West. At times the survey

party numbered 700 people.[2]

Baseline measurement[edit]

The initial baseline was measured with great accuracy, since the accuracy of the subsequentsurvey was critically dependent upon it. Various corrections were applied, principally

temperature. An especially accurate folding chain was used, laid on horizontal tables, all shaded

from the sun and with a constant tension.

Corrections[edit]

To achieve the highest accuracy a number of corrections were applied to all distances calculatedfrom simple trigonometry:

Curvature of the earth

http://en.wikipedia.org/wiki/Thomas_Tupper_Carter-Campbell_of_Possilhttp://en.wikipedia.org/wiki/Chennaihttp://en.wikipedia.org/wiki/St._Thomas_Mounthttp://en.wikipedia.org/wiki/Tellicherryhttp://en.wikipedia.org/wiki/Kannurhttp://en.wikipedia.org/wiki/Ezhimala_Hillhttp://en.wikipedia.org/wiki/Tadiandamolhttp://en.wikipedia.org/wiki/Great_Trigonometric_Survey#cite_note-markham-1http://en.wikipedia.org/wiki/Great_Trigonometric_Survey#cite_note-markham-1http://en.wikipedia.org/wiki/Great_Trigonometric_Survey#cite_note-markham-1http://en.wikipedia.org/wiki/East_India_Companyhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Triangulationhttp://en.wikipedia.org/wiki/Great_Trigonometric_Survey#cite_note-2http://en.wikipedia.org/wiki/Great_Trigonometric_Survey#cite_note-2http://en.wikipedia.org/wiki/Great_Trigonometric_Survey#cite_note-2http://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=2http://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=3http://en.wikipedia.org/wiki/Curvature_of_the_earthhttp://en.wikipedia.org/wiki/File:Colonel_thomas_tupper_carter-campbell_of_possil.JPGhttp://en.wikipedia.org/wiki/File:Colonel_thomas_tupper_carter-campbell_of_possil.JPGhttp://en.wikipedia.org/wiki/File:Colonel_thomas_tupper_carter-campbell_of_possil.JPGhttp://en.wikipedia.org/wiki/File:Colonel_thomas_tupper_carter-campbell_of_possil.JPGhttp://en.wikipedia.org/wiki/Curvature_of_the_earthhttp://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=3http://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=2http://en.wikipedia.org/wiki/Great_Trigonometric_Survey#cite_note-2http://en.wikipedia.org/wiki/Triangulationhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/East_India_Companyhttp://en.wikipedia.org/wiki/Great_Trigonometric_Survey#cite_note-markham-1http://en.wikipedia.org/wiki/Tadiandamolhttp://en.wikipedia.org/wiki/Ezhimala_Hillhttp://en.wikipedia.org/wiki/Kannurhttp://en.wikipedia.org/wiki/Tellicherryhttp://en.wikipedia.org/wiki/St._Thomas_Mounthttp://en.wikipedia.org/wiki/Chennaihttp://en.wikipedia.org/wiki/Thomas_Tupper_Carter-Campbell_of_Possil

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The non sphericalnature of the curvature of the earth Gravitational influence of mountains onpendulums Refraction Height above sea level

Superintendents[edit]

181823William Lambton 182343Sir George Everest 184361Andrew Scott Waugh 186184James Thomas Walker 18851911Sidney Gerald Burrard 191221Sir Gerald Ponsonby Lenox-Conyngham

Land purchases by surveyors [edit]

Many surveyors became very rich. Prominent among them was Andrew Chamrette, his son PeterChamrette, and his grandson Charles Chamrette, who worked for the GTS of India from 1802 to

1876. This family acquired in excess than 1,800 acres (7.3 km2) of land in the Kapsi,Yavatmal

and Maharashtra (formerly CP Berar) districts.George Everestbought 600 acres (2.4 km2) of

land nearDehra Doon.

http://en.wikipedia.org/wiki/Figure_of_the_Earthhttp://en.wikipedia.org/wiki/Gravitationhttp://en.wikipedia.org/wiki/Pendulumhttp://en.wikipedia.org/wiki/Refractionhttp://en.wikipedia.org/wiki/Height_above_sea_levelhttp://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=4http://en.wikipedia.org/wiki/William_Lambtonhttp://en.wikipedia.org/wiki/George_Everesthttp://en.wikipedia.org/wiki/Andrew_Scott_Waughhttp://en.wikipedia.org/wiki/James_Walker_(Surveyor_General)http://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=5http://en.wikipedia.org/wiki/Yavatmalhttp://en.wikipedia.org/wiki/George_Everesthttp://en.wikipedia.org/wiki/Dehra_Doonhttp://en.wikipedia.org/wiki/Dehra_Doonhttp://en.wikipedia.org/wiki/George_Everesthttp://en.wikipedia.org/wiki/Yavatmalhttp://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=5http://en.wikipedia.org/wiki/James_Walker_(Surveyor_General)http://en.wikipedia.org/wiki/Andrew_Scott_Waughhttp://en.wikipedia.org/wiki/George_Everesthttp://en.wikipedia.org/wiki/William_Lambtonhttp://en.wikipedia.org/w/index.php?title=Great_Trigonometric_Survey&action=edit&section=4http://en.wikipedia.org/wiki/Height_above_sea_levelhttp://en.wikipedia.org/wiki/Refractionhttp://en.wikipedia.org/wiki/Pendulumhttp://en.wikipedia.org/wiki/Gravitationhttp://en.wikipedia.org/wiki/Figure_of_the_Earth