My opinion is that the background noise will not be seriously high unless normal traffic begins to reach such heights that it will create the same type of disturbance as the projectiles which we are considering.
f) Measurements of actual sound channel transmission using a small stratosphere balloon carrying sound receivers and a radio for transmission of sound signals to a recording station should be the next step in this investigation.
VII CONCLUSIONS
it is my opinion that the stratosphere sound channel should be investigated, for it has the potentiality of military importance. I believe that its military importance depends greatly upon secrecy and that the investigation should be started in a quiet way, restricting knowledge of the purpose of the work to the smallest possible group.
VIII REFERENCES
1. Interim Report No. 1 Long Range Sound Transmission, by Maurice Lwing and J. L. Korzel, Contract NObs-2083, Bureau of Ships, Navy Department, 1945.
2. Handbuch der Experimentalphysik, by C. Meisser, pp 211-251, XXV, 5 Teil Luftseismik, Hien & Harms, Lolpsig, 1930.
3. Theory of Sound, by Lord Kayleigh, vol. II, pp. 316-17, Macmillan & Co., London, 1826.