#10 in the Tom Swift Jr. series. Grosset and Dunlap hardcover publication. Copyright 1957. Print year is estimated at 1962, based on publishing date of #20 Megascope Space Prober, listed as the last title on the rear cover and the internal book list. Author "Victor Appleton II." Victor Appleton the first was the Stratemeyer Syndicate pen name for the initial Tom Swift series. Good book with good spine and hinges, but with tracking at front hinge. Blue and white space lab endpapers. Storage-soiled side and bottom page blocks (see pictures). No writing/markings. Some corner wear. There's a bend at the top right front cover. In this one, Tom develops the drumhawk, a craft that uses ultrasonic rotating drums to provide lift. He uses it on a dangerous rescue mission. Note to New York state residents: an 8.75% sales tax is applicable. (TSC10)