Hoover's first book. Wildly successful, often reprinted, and still available.
"True" First Edition (in my observation) has: "Hill Publishing Company" (soon to become McGraw Hill) on the spine and title page; no reference to "edition" or subsequent printings, impressions, or thousands; and most interesting, in the second line of the PREFACE, "Stamford" instead of "Stanford" (Columbia is spelled properly). The copies I've seen have a pencil line through the "m" of "Stamford" -- perhaps an informal correction after printing. There could be, of course, other typos.
Pages vii and 1-199 numbered. Issued, I think, without dust-jacket.
Stanford, Cornell Engineering, Harvard, LOC. and perhaps others have "True" First Editions; others are mostly later. HathiTrust and Gutenberg have 14 digitizations but only 2 "True" First Editions (Cornell and Harvard).