It is seen that the U. S. map gives data consistent to better than +0. 1 percent, while the Japanese chart is internally inconsistent to something like 1.0 percent. Scaling on the chart between known islands which retain the same shape on both charts, we get the following ranges in feet: _ + twee North end, Parry - South end, Engebi 100,300 100, 100 -0.2% | North end, Parry - Rigili South edge, Eniwetok -center Elugelab 102, 700 128,700 102,900 127,900 +0.2% - 0.6% | Parry tower - Elugelab 114, 050 113,950 7 9.1% 12. Meteorological Data The U.S. Air Force, in support of the AEC, will fly weather -sounding balloons shortly before shot time, from Eniwetok Island. These balloons will radio to ground receivers data as to the air pressure, temperature, and dew point as functions of altitude. Although Eniwetok Island is more than twenty miles from the point of burst, it is certain that the meteorological data so obtained represent co:ditions above the bomb within the prescribed limits of error. In order that the U. N. Observers may have a check-reading as to air density, the USAEC will provide a mercury barometer anda sling-psychrom- eter so that these data may be obtained at ground level on Parry Island. The determination of air density from the given raw data is treated ~ in the literature; tables will be provided to help in the reduction of data. 13. Films Photographyof the Pinon shot will be accomplished by meansof special emulsions manufactured by the Eastman Kodak Company. These films are Similar to commercial Microfile film, used as a high-contrast, high- resolution material in microfilming documents and records. For the purposes of fireball photography the special Microfile is provided with a Panchromatic, rather than Orthochromatic, spectral response. This film, identified as Nike S.O. 918", has a response from about 0. 4 to 0. 7. microns, The emulsion is very thin, and is coated by machine on standard acetate base; it can also be obtained on glass plates. -19.-