Good fun -- good period -- good yarn, whose historical basis (Philadelphia of , with and feeling flaming high) adds to the interest. One feels the heritage of Tom Nawyer and Penrod in young Tack Bingham, his troubles with boastfulness, with his parents, schoolfellows, and instructors, with the escapades in which he is involved, in his connection with the inventor, Oliver Evans, whose Orkuter Amphiboles was the first steam ever male or seen in the United States. Fiction and fact neatly blended. There is a pirate -- a love affair -- the machine that plays a g's part -- a threatened kidnapping -- and Tack's attempts to make good his promise to build a flying machine. Grand reading for all the family.