Humboldt and Boussingault on Chimborazo: how high did they climb?

Work on my book about Chimborazo (and our cycling and climbing adventures in Ecuador) continues apace. I have now received all my feedback from beta readers and am working on the 4th draft, which involves more cuts and changes as I make edits to the flow and tone of voice.

Writing a book involves a lot of butchery. With Seven Steps from Snowdon to Everest I wrote 180,000 words initially, then ruthlessly chopped it down to 117,000 for the final version. My first draft of Chimborazo had 140,000...