Published herein are the papers presented at the second annual AFCRL Scientific Balloon Symposium covering the advances shown in balloon design, materials, instrumentation, meteorology, and scientific applications since the last symposium held in Boston on 25, 26 and 27 September 1963. Balloon technology presentations include stress studies, new balloon films, sensing elements, telemetry systems and a new balloon locating system. Applications and experience in working with tethered, meteorological and sounding balloons are discussed. In addition, information is presented on such existing programs as BAL-AST, and Surveyor and such proposed projects as the "AFCRL Stratospheric Humidity Program" and "The Mars Balloon."

This review constitutes a revision and up-dating of the report, Atmospheric Structure and its Variations in the Lower Thermosphere (AD-417 201). It has been prepared for inclusion as an appendix in the proposed new edition of the COSPAR International Reference Atmosphere (CIRA). New density data presented and discussed include the results of four falling-sphere density measurements made at White Sands, New Mexico, and densities deduced from drag effects on Explorer XVII and other satellites. The satellite density data is compared with the predictions of several models of Jacchia and Harris and Priester. Temperature data include revised values deduced by Blamont from Doppler broadening of sodium and potassium resonance lines. The new values are in better agreement with theoretical models than the earlier results. Recent composition results include number densities of O2, N2 and O calculated from ultraviolet absorption measurements by Hinteregger, and values of mean molecular mass from Explorer XVII and the rocket measurements of Nier and Schaefer. (Author).

A short review is given of the literature pertinent to the bolometric correction. A recommended scale of bolometric corrections is presented based upon recent model atmospheres for stars of early spectral type, and upon stellar energy distributions synthesized from photoelectric observations of stars later than FO V. The reduction of various photoelectrically determined magnitude and color systems to a common system and the further reduction of these measurements to absolute energy units is discussed in some detail. (Author).

An empirical relationship between the area in which a given dosage is equalled or exceeded and the value of the dosage itself are developed using Green Glow data. It is found that the logarithm of the area is nearly a linear function of the logarithm of the dosage divided by the source strength and multiplied by a representative wind speed. These results differ only slightly from similar results obtained from Prairie Grass data. Observations of the time of first arrival of the tracer near ground level at distances of 8 and 16 miles from the source indicate that the tracer material which first arrives has travelled with a wind speed greater than the surface wind (about 15 ft). It would be necessary to have wind speed measurements between 50 and 100 ft above ground in order to estimate the time of first arrival at these distances even though the source is no higher than 15 ft.