In the past the Northern frontiers of India were not only dangerous to mountaineers, but because of the suspicion and hosility of the people of Tibet, Nepal and Afghanistan. The survey of India - twenty seven times larger than England and Wales - was a vast undertaking of two hundred years and an adventurous odyssey. The author, who has climbed in the Himalayas, tells the story of India's survey and of the men who completed it against appalling handicaps and dangers.