The title is explained in an excerpt from the “Spaceman’s Handbook” used as a foreword:
SEETEE (from CONTRATERRENE, CT). An inverted type of matter… Seetee atoms are inside out, electrically, with negative nuclei and positive atoms.
Or what we today call antimatter. Contraterrene seems to have popped into use in 1940 and Williamson picked up on it for a series of stories printed in Astounding Science Fiction starting in 1942, all written under the pseudonym Will Stewart, the only time he used that name. Insiders probably got the joke, since his birth name is John Stewart Williamson. Williamson apparently invented “seetee” as a term. Several other writers have used it since, but it’s rare enough that most modern readers would stumble over it.
“Collision Orbit,” July 1942, “Minus Sign,” November 1942, and “Opposites—React!” January and February 1943, were combined to make up a novel, Seetee Ship. A second novel, Seetee Shock, was serialized in Astounding in 1949 and published as a book in 1950. It’s a sequel, even though it saw print first. Unusually for Gnome, other Williamson books are listed on the pre-title page, presumably to let readers know about the pseudonym. The first book listed is Seetee Shock, and then five others are as by Jack Williamson.
This book starts two pleasant graphical traditions for Gnome. The spine contains a drawing of a space-helmeted gnome riding a rocket-powered book. It’s almost invisible here but would become more prominent on future titles. And the title page is a doodle-like figure of a soaring ship, repeated on the copyright page, that is presumably a speeding seetee ship. Small graphics reflecting the nature of the book pepped up future title pages as well.
Groff Conklin reviewed it for the November 1951 Galaxy:
It’s a good story if you can bear plowing through pages of literary corn starch.
Seetee Ship, by Will Stewart (pseud. of Jack Williamson), 1951, title #12, 255 pages, $2.75. 4000 hardbound copies printed.
Hardback, black cloth with orange lettering. Jacket design by Edd Cartier. “First Edition” stated on copyright page. Colonial Press, Printers. Back cover: 10 titles. Gnome Press address given as 80 East 11th St., N.Y. 3.