ACKNOWLEDGEMENT
We wish to thank Dr. G. P. Kuiper, Director of Yerken Observatory and consultant to the Physics Division of ARF, for a number of very enlightening discussions of this work centering especially around interpretation of various theories of the moon's structure and origin and descriptions of the probable nature of the lunar surface. During initial phases of the work, Dr. Kaj Strand, Director of the Naval Research Observatory and also a consultant to ARF, contributed valuable advice, especially on spectroscopic problems. W. E. Loewe of ARF gave helpful administrative assistance, Throughout the project Lt. A. Guenther of AFSWC provided constant encouragement and considerable assistance.
