Concerns Salmon's conic sections: In correspondence with Fiedler,
who was to do German editions, Salmon writes that he is required to treat
circles at length because of the University requirements; he suggests that
F. cut back on this for the German version. This seems to confirm
David Wilkins' surmise of the role of this work.
Salmon's Conic Sections is significantly updated in the second
english edition. I would think that from then on it was a (the?) main
force of modernization in English college math teaching. (There are
further changes of note in later editions.)
(Let's also remember that Felix Klein credits his learning of
geometry to Salmon's texts ---In Fiedler's german versions.)
Best to all from cloudy-windy Pittsburgh,
Ken Manders