Philadelphia: John C. Winston Co., (1952) dj. Hardcover first edition - A speculative look at exploring the last frontier on earth- the depths of the ocean - and the "terrors of life seven miles under the sea faced by men who fought to save the North American continent from disaster." A title in the classic Winston series of juvenile science fiction, written by some of those who would go on to be among the most respected writers in the genre, and by those with a knowledge of and background in science. Endpaper design by Alex Schomburg. Cecile Matschat and Carl Carmer, series editors. Dust jacket by Paul Orban. Manufacturing Division's file copy with a bookplate on front endpaper.