Surveyor Follows Historic India Mapping Survey
Most land surveyors at some point in their career wind up researching historic field notes, land records or plats from some earlier era. Depending on your area of practice, research may include GLO field notes, NGS control surveys, Native American tribal lands, Spanish or Mexican land grants, metes and bounds in the Colonial states, grant deeds, etc. Researching GLO field notes in my area of California’s Central Coast, I was always drawn to the first couple of pages with the names of long-gone surveyors and their crew assignments, i.e. party chief, instrument, compass or chain men, possibly a few axe men, maybe even a hunter and/or a camp keeper (cook). And before you or any former clients read this, no billable time was consumed developing the following story.
My curiosity piqued about surveying under those conditions, when an internet search for more historical information happened to turn up a July 1992 article about Sir George Everest and the survey of India by Mary M. Root. Reading the article about the world’s greatest triangulation survey of that era, and Sir George’s relentless pursuit of accuracy, I went looking for more information.
This six-decade-long survey is covered in the book, “The Great Arc” by John Keay. It’s the story of the survey of the Indian subcontinent from 1802 through 1855. This well written and enjoyable book tells the story of the British East India Company’s need for mapping as they acquired and colonized the many Indian principalities within that country’s vast interior during the 18th and 19th centuries. Begun by Wm. Lambton in 1802, the survey continued until his retirement in 1823, and was continued by Sir George Everest. The survey ran until his retirement due to health reasons in 1843 and was completed by Andrew Waugh in 1855.
The Great Arc roughly followed the 78th East Meridian from Cape Comorin at India’s southern tip north to the foothills of the Himalayas. Keay, though not a surveyor, explains geodetic survey principles in an interesting way for readers to get an idea of magnitude and immense difficulty of the survey.
Understanding the Survey’s Scope
I began to understand the magnitude of the Great Arc survey with the book’s description of the first base line. Lambton’s crew began the survey, taking 58 days to complete a 7½-mile-long precision base line (measured with a 100-foot chain) near the southern beginning of the survey route, with additional baselines throughout the network for adjustment purposes. Principal triangulation points throughout the network were selected for astronomic observations and geodetic positioning. Triangulation lengths varied according to terrain, with 20 miles being the desired length on the 1,600 mile survey. Sometimes weeks passed waiting for crews to establish signal towers on a distant hill or ridge, including delays waiting for suitable observation weather.
Theodolites weighing half a ton were hoisted to the top of bamboo or stone towers, the tops of temples or mountain tops, with weather ranging from blistering heat and humidity in the jungle lowlands to blizzard conditions in the Himalaya Mountains near the northern border with Tibet and China. Malaria, yellow fever, and other diseases wiped out entire survey crews while marauding tigers, scorpions and cobras pecked away at individual surveyors. The survey of the Great Arc made possible the development of harbors, roads, railways and telegraphs defining India as we know it today.
The Great Arc survey also made possible the first accurate measurement of the Himalayas, including Mt. Everest, K2, Dhauligiri, and other principal Himalayan peaks and, more importantly, new, accurate values for the curvature and shape of the earth. The sheer size of the survey included logarithmic calculations for spherical excess, effects of the geoid on precise leveling and atmospheric refraction.
Following Early Footsteps
After concluding the sale of our business in 2015, my business partner and I booked a month-long tour of Rajasthan, India during February 2016, including an additional week to further explore Delhi on our own. Rereading Keay’s “The Great Arc” prior to our trip, there was a picture taken years ago of a 13th century structure used by Everest as a triangulation station within an area known as “The Ridge,” just northwest of Delhi’s city center. On our final day in Delhi, we hired a car to see if we could locate this station, aided by clues from the book (adjacent to the Hindu Rao Hospital).
With more than a bit of luck, we found the hospital on the ridge. Asking around the hospital offices, we were sent from office to office until we found an administrator who called a maintenance man who walked us to the fenced off area, unlocked the gate and let us wander around the structure. The structure is an Indian national monument, but doesn’t appear to be visited often.
Climbing up a steep stairway to the top, we found the remains of a large mortared pad for Everest’s theodolite with a vertical hole through the roof and, according to the book, a monument on the floor below. There were squatters occupying the structure so we stopped short of looking for the actual monument. This was an exciting end to a great month in India and created more personal interest with Everest’s career-long survey.
A Second Attempt
Keay’s book includes photos of instruments used by Lambton, Everest, and others during the survey that are located within a museum at the Survey of India (India’s version of our own NGS) facility in Dehra Dun India where Everest had established the agency’s permanent offices in the 1830s.
Returning to the Indian subcontinent in September 2016 to join a trekking group in Nepal, I wondered about my chances of visiting the Survey of India offices following the completion of my trek. The Survey of India campus is not only India’s Defense Mapping Agency, it is also a university campus, training all of India’s land surveyors, photogrammetric surveyors and land information professionals. My plan was for a three-day stay in Dehra Dun to see what I could find and visit the museum, the offices, and possibly Everest’s house, which is an hour’s drive north into the Himalayan foothills.
Email efforts to contact anyone in the Survey of India office before leaving home were not successful… or so I thought.
With departure time fast approaching, a friend suggested I try contacting the author, John Keay. Despite a surveyor’s normal skepticism with any suggestion, I emailed Keay explaining what I was trying to accomplish. Within hours, I received a very pleasant reply with suggestions for my visit including contact information for a Sikh lady that was the SOI historian years ago during Keay’s research for his book. Two days later, I was on my way from SFO to Kolkota, India, still with no word from the Survey of India offices.
Three weeks later, following travels through West Bengal and my Nepal trek, I flew from Kathmandu to Delhi with a connection flight to Dehra Dun, still with no word. I checked into a local hotel within walking distance of the SOI campus with hopes for good luck the next day. Talking to the hotel manager that evening, I learned the SOI campus is a secure environment because of ongoing political tensions with Pakistan and China, and thus, it would be difficult to gain access. Not what I wanted to hear.
In the morning after breakfast, I walked the hour or so to the main gate and was stopped by armed guards who explained to me that access for anyone, especially a foreigner, was impossible without written permission from the surveyor general of India’s office. Recalling Keay’s suggestion to be persistent, I was finally escorted by an armed guard to an interior office after surrendering my ID, passport, camera and phone. With the gate closed and locked behind me, I was inside with no idea of what was about to happen next.
Taken to the office of R.M. Ghildayl, supervising office surveyor, I explained why I was there and my interest in the early survey, and told him that I would like to visit the facility museum. Ghildayl pleasantly explained to me that he was very busy, had no knowledge of historical data related to Everest’s work, and would be happy if I would maybe just go away.
Trying everything I could think of, I played my only trump card and mentioned Keay’s recommendation of the historian. Ghildayl lit up and instantly became very friendly. She had retired, he explained, and he shared her mobile number with me. The ice broken, he pushed a button on his desk, and an older gentleman came in and sat on the floor to brew us both a cup of tea.
We talked about survey experiences – in particular, his field work in the 1970s along the Nepal and West Bengal border in the Himalayas. It was very interesting. We have similar stories about techniques and equipment from an earlier time. A half hour later, Ghildayl escorted me to the door, wished me luck and returned to his work. Signing out at the main gate, I walked back to my hotel with the feeling that I might have my foot in the door.
Following lunch at the hotel restaurant, I decided to book a hired car the next day to travel to Mussoorie in the Himalayan foothills to see if I could locate Sir George Everest’s home. The gentleman at the front desk arranged for a driver to pick me up in the morning. That evening, I called the historian’s mobile number. She was very pleasant and said she would try to meet with me the next day.
With part of the dream realized, the quest continues in Part 2.