William Lambton was in his mid-40s, having made a name for himself as a geographer and a geodesist during the determination of the border between USA and Canada after the American War of Independence. By 1799, he was back in India, as Lieutenant Lambton, having taken part in the success of the British in the Anglo-Mysore War. Though his initial proposal was to survey the newly acquired territories of Mysore, he quickly expanded its scope to cover a much larger area. But even at that time, it is doubtful that Lambton could have imagined the enormity of the project. Originally planned to be done in five years, it took 60 years for it to be closed. And it changed the face of the earth, quite literally, justifying its name as the "Great Indian Trigonometrical Survey". It was a project that mapped the entire subcontinent, using theodolites, triangulation and trigonometric tables. In the course of its progress, it 'discovered' the Chomolungma mountain, the highest point on land. That point, designated as Peak XV during the survey, was named after Lambton's successor as Survey Superintendent: the world knows it today as Mount Everest.
And that's how Mount Everest connects with Chennai's own St Thomas' Mount. That Great Indian Trigonometrical Survey began on April 10, 1802, with the first measurement from the top of St Thomas' Mount. The man who conceptualised it, Col William Lambton, spent the second half of his life in the field, making the survey happen. If we take the inscription on the pedestal of his bust at St Thomas' Mount as being accurate, Lambton was 80 when he died on January 30, 1833. Many other biographies date his death to 1823. Whatever be the case, Col Lambton had initiated such a compelling endeavour that the East India Company and later the British crown funded it until it was completed.
Col Lambton's bust at the top of St Thomas' Mount is a tribute to the survey itself, as much as it is to him. The next time you go up on to the mountain, make sure you spare a moment for this man!