The Invention of Nature - Reading Update: Part 4

At the end of July, more than three months after leaving Berlin, Humboldt reached Tobolsk – 1,800 miles from St Petersburg and the most easterly point on the prescribed route – but it was still not wild enough for his taste. Humboldt had not come this far only to have to turn around. He had other plans. Instead of travelling back to St Petersburg as previously agreed, Humboldt now ignored Cancrin’s instructions and added a detour of 2,000 miles. He wanted see the Altai Mountains in the east where Russia, China and Mongolia met, as the counterpart to his observations in the Andes. As he had failed to see the Himalaya, the Altai was as close as he could get to collecting data from a mountain range in Central Asia.
I'm finding it hard to put this book down. He is such an unlikely rebel, and yet...he gets away with it.
Having been denied access to the Himalayas by the East India Company, and having returned to Berlin, Humboldt is dying to get out again.
I was so relieved when I read about his travels through Russia. Not only because the parts where he travels have been my favourites of the book, but also because I really hate seeing him cooped up.
And of course there several passages where I caught my breath, most notably where he basically upsets Cancrin, the czar's official delegate, by wanting to see the true living conditions of the eastern peasants and, the second, where he is so set on reaching his destination (also against the will of Cancrin) that he rode straight through a region plagued with an anthrax epidemic. Anthrax!!! WTF, Alex?
"As they sat in silence, hot and cramped behind tightly shut windows in their small carriages, they passed through a landscape of death. The ‘traces of the pest’ were everywhere, Humboldt’s companion Gustav Rose noted in his diary. Fires burned at the entrances and exits of the villages as a ritual to ‘clean the air’. They saw small makeshift hospitals and dead animals lying in the fields. In one small village alone, 500 horses had died."
I guess the views would have have been worth it:
As for the other parts, I enjoyed learning about how much Humboldt had influenced Darwin. I had never expected this.
I am, however, puzzled by the chapter about Thoreau. Not only was this the least interesting to me, but I found the description of Thoreau quite annoying.
While Humboldt and Darwin were scientists who were able to write well, Thoreau merely strikes me as a - somewhat lofty and self-indulgent - writer, but not really a scientist.
What was the point of including this chapter other than to illustrate Humboldt's influence across several continents?