Well, finally got around to Amazoning for "Northwest Passage" and "Robert Rogers" -- "Northwest Passage" is avail. in dead-tree format, but no ebook format.
There is a John Ross bio of Rogers avail. in Kindle format for such a deal... $16.50 ebook and $19.80 deadtree.
Now, I currently got hit with a surprise.. Theodore Roosevelt was a very engaging scholar of military affairs. Im reading a badly-formatted Gutenberg version of his study of the naval battles of the War of 1812. Wish there were a better copy around. The footnotes, of which TR was apparently quite fond, appear in the body of the text and the tabular formatting is useless.