Each generation throws up a passion for doing something unique and throughout the 19th century it was the accurate measurement of the dimensions of the earth with the aim of locating important geographical features in terms of latitude and longitude. After all, who we are, is intimately associated with where we are.
In April 1802, the relatively comfortable cool days of winter were giving way to rising temperatures and increasing humidity while the sultry Indian summer loomed endlessly ahead. As fellow British officers explored ways to escape the heat, Colonel William Lambton made plans to measure the Empire’s greatest treasure as well as the curvature of the earth . He hoped to settle the argument about the shape of the earth – is it a ball or is it a grapefruit? This ambitious and seemingly impossible plan was to measure the arc of the meridian, by trigonometric survey. Little did he know at the time that the task would take nearly 50 years and it would be his successor, George Everest (after whom a small mountain was named), who would see it finally completed, while Lambton, the father of the survey, would be long forgotten.
Malaria, tigers, swamp fever and a host of other ills took their toll but the survey, in the true British never-give-up-spirit, marched on and on mapping the sub-continent from the tip of India in the south to the very Himalayas themselves.
The 2,500 kilometres of inch-perfect surveying was, and still remains, one of the greatest human endeavours ever undertaken. Braving forest, flood and fever for nearly 50 years, the British surveyors and their Indian staff carried instruments weighing more than half a ton to make possible the mapping of the entire Indian sub-continent. Half-a-century of dedicated effort consumed the lives of more men than most contemporary wars.
The equations that they used to calculate the curvature of the earth are more complex than any that had been formulated in the pre-computer age, and have been likened to as much of a technological achievement as man stepping foot on the moon in 1969. Precision was the mantra; and it was so rigorously maintained that even today, despite more sophisticated mapping equipment and survey methods, the values arrived at then, using those techniques, cannot be disputed.
The plan succeeded, and today, nearly 200 years later, we will celebrate and acknowledge the creation of what has come to be known as The Great Arc, by driving parallel to the 78’ meridian, upon which, modern mapping and surveying of the Indian peninsula is still based.
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