quickly. One sheet of paper will summarize the magnification parameters: horizontal distance: camera tilt: L 7 optic-axis distance: L- cos T camera focal lengths: f camera magnifications: L-+ cos 7/f, and the Hauser magnifications for each objective. Another sheet will summarize the meteorological data, and will tabulate air density p, and the fifth-root of the density, as functions of altitude; the fifth-root data will also be plotted on graph paper against altitude. Four additional sheets, one for each film, will tabulate for each picture measured: the time and image diameter, the corresponding object diameter, D the parameter ¢ =D. 1-2/5, and also op,1/5 Tables giving 1-2/5 as a function of t, will be provided to aid these last two determinations, and the density chosen will correspond to analtitude equal to one-fourth the diameter. The computed parameter will be plotted against log (time) to deter-. mine the interval over which it is essentially constant. Finally an average figure will be determined for 1/5, over the indicated time interval and over all four cameras; this value will be raised to the fifth power and multiplied by +x 1.272 x 1078 to obtain the total energy release in kilotons. -37-