Yes, he is a fine author who uses many words that are new to me, and he's not just rodomontading, either. [dig e]
Here's the quote the site has: As if in a minor earthquake, the truck trembled for minutes after he was gone, its corrosive fluid seiching back and forth.
I notice, though, that at one point the writer (on the site, not Mr. McPhee) says "an 1839", and in another place he has "a 1864". I saw the latter first, and wondered if it was some variant usage.