||Orthography is in accordance with the orders of the government of India, dated 3rd September 1875,
Conventional Signs. Trigonometrical Stations ▲ Intersected Points and Traverse Stations ○ State Boundaries ~~ Edge of forest clearance ☁ Heights above mean sea level determined trigonometrically thus 752 relative heights in feet of banks to beds of water-courses thus 15 r The Linear values are derived from the measured length of the sironj base, assumed as log. feet 4.5844824, through the karachi longitudinal series.
The heights are referrible to Mean Sea Level at Okha Tidal Station on the Gulf of Cutch.
The Longitudes are referrible to Madras Observatory, 80° 17' 21 to which a correction of - 2' 30 must be applied to reduce to the most recent value, viz : 80° 14' 51