Ebenezer Prout's Harmony

Just wondering if anybody else has read Ebenezer Prout's book on
Harmony and what their take on it is.  I've read it through twice and
completed all the exercises in it.  I have found it an invaluable aid
to my own compositions and understanding of harmony.  Of the books on
harmony that I've read I have found that it is the most complete.  In
particular, I find his system of deriving chromatic discords very
interesting.  It is logical and uncomplicated.  After studying his
book I was able to analyze and give a logical function to chords that
previously I had to explain away with such vague terms like "non-
functional chord progressions" or "chromatic mediants" and the like.
I often wonder while so few of the theorists I talk to have not read
or even heard of this book and the ones that do are very indifferent
towards it.  I learned more from that book than in four semesters of
music theory in college.  It bothers me that this book apparently
receives so little credit and that we place books on 18th/19th century
harmony written in the 20th century above this one.  Prout was
writting about the system of harmony that was in use during his time
and that he composed in, not reflecting back on a system that was
falling out of use and viewed as a relic of the past.  Therefore,
should he not have a better understanding of it than any of the 20th
century authors on harmony?