THE HUNNIWELL BOYS AND THE PLATINUM MYSTERY #4 in series.
Edition: Early printing.
New York: A. L. Burt, (1928). Hardcover - The fourth book in this "thrilling aviation series for boys 12 to 16 years." Features Bill and Gordon Hunniwell, two enterprising and inventive young Americans who have many thrills in their new electric airplane. Five titles listed at front of book and in ads at rear. Glossy frontispiece, 218 pp plus 6 pp publisher's ad.
Condition: Good condition overall in illustrated tan cloth (gift inscription dated Christmas 1929, 1 leaf of ads partially detached, some wear to covers, but a straight tight copy, no dust jacket)