PEBBLE IN THE SKY, Doubleday, 1950, first edition, just about fine in like dust-wrapper with 2 closed tears. The authors first book (save for THE KINETICS OF THE REACTION INACTIVATION OF TYROSINASE DURING ITS CATALYSIS OF THE AEROBIC OXIDATION OF CATECHOL, the author's Ph.D Dissertation first published in 1948) in a long and marvelous career which unfortunately came to a premature halt just about 500 books later.