Answer:
John Muir personified the wind and trees as humans with "arms caressing" the leaves and other things.
He personifies them to make things more realistic for the readers to be able to more easily comprehend the story.
Explanation:
Personification is the figurative language or technique used by an author to give human attributes to the abstract or non-human qualities. This allows the ideas or abstract themes to have human characters/ qualities, thereby allowing them the image of something that is easier to comprehend.
John Muir's "Mountains of California" is a book that details the beauty of the most remote yet beautiful places of America. John Muir is a preservationist who works related to the conservation and preservation of nature. In chapter 10 titled "A Windstorm in the Forest", he used personification in describing the wind. He personifies the wind as <em>"fingering every leaf and branch and furrowed bole"</em>, "<em>Mountain Pine towering with outstretched arms on the rugged buttresses of the icy peaks</em>".
He personifies them to show the realistic nature of his story. He uses this technique to describe the ways of nature and to make the story more comprehensible to the readers. It allows a reader to imagine the story just as it should be, and thus making a better representation of the story.