Herman Melville - The Confidence Man
http://www.online-literature.com/melville/confidence-man/10On the floor are many copies, looking as if fluttered down from a balloon. The way they came there was this: A somewhat elderly person, in the quaker dress, had quietly passed through the cabin, and, much in the manner of those railway book-peddlers who precede their proffers of sale by a distribution of puffs, direct or indirect, of the volumes to follow, had, without speaking, handed about the odes, which, for the most part, after a cursory glance, had been disrespectfully tossed aside, as no doubt, the moonstruck production of some wandering rhapsodist.
by "as no doubt, the moonstruck..."
does he mean
"as if no doubt being the moonstruck..."?
Was he using an ellipsis, I don't understand the reason he formulated this sentence such as he did, can you explain?