Text this: Introductory statement; I. Sounding balloon ascensions at Fort Omaha, Nebr., May 8, 1915; II. Meteorological observations on board U.S.C.G. cutter "Seneca," Apr.-July 1915; III. Drexel Aerological Station; IV. Free-air data at Drexel Aerological Station, Oct., Nov., and Dec. 1915.