What is the author's tone in The Wild Muir: Twenty-two of John Muir's Greatest Adventures by John Muir?

Muir's tone is unusual for one who lived such a wild, risky, and unusual life. Most of Muir's articles are taken from his journal entries but unlike many journal entries, Muir's entries are not very personal. He only sometimes makes observations on his own conditions and sometimes his mental states, but mostly with respect to bodily sensations, fear, and exhilaration. Muir says little about his internal dialogue and in fact, focuses very little on anything but what he senses and observes.