How and when was Everest determined to be the tallest mountain in the world?

Factual Questions
1

I guess the answers go hand in hand–when did technology–and geography–reach the point that Everest could be determined as the tallest? And the specific instruments used?

2

Not an answer to your question, but . . .

There’s a book called “Into Thin Air” by a guy named John Krakauer. The book is about a climb of Mount Everest that went horribly wrong, killing many people.

As I recall, the first chapter has a fabulous description of the surveying process done by the British in colonial India, how they measured the heights of mountains and named them, and how they concluded that Everest was tallest.

3

Colonel Andrew Waugh (a British military engineer and surveyor general of India) and his staff surveyed the peak between 1847 and 1852, using standard surveying equipment – theodolite, measuring rods, chains, trigonometry, and the baseline measurements made by his predecessor, Sir George Everest. The equipment and science of surveying had been around for centuries before this – the Egyptians did it – but the theodolite was invented in 1721 (the modern transit was invented in 1831). It was the task of getting to a place where measurements could be made, however, that was the limiting factor in India.

Here are some sites on surveying, Mt. Everest, and Sir George:
http://www.sbg.ac.at/mat/staff/revers/mallory105.html
http://www.surveyhistory.org/sir_george_everest.htm
http://www.surveyhistory.org/the_changing_chains.htm

4

The story of Lambton, Everest and the Survey of India is told in John Keay’s popular The Great Arc (Harper Collins, 2000). Waugh’s extension of their work into the Himalayas forms the final chapter.
Personally, I felt the book is flawed - there’s a whole scientific context that he misses and it seems rather anglocentric - but it’s certainly a very readable and colourful account of the tribulations faced by the surveyors.

5

“Peak XV”, as it was then known by the surveyors, was first determined to be the highest mountain in the world in 1852. So says this page: http://www.cbc.ca/news/indepth/background/mount_everest.html

The work was part of the Great Survey of India, done using triangulation from a fixed baseline. I’m sure you can find plenty of info on this if you do a web search.