258 ANNUAL REPORT SMITHSONIAN INSTITUTION, 195 7 



proven fact and hypothesis. By thus stepping over into unexplored 

 areas, we can see more clearly the exciting possibilities of future re- 

 search and, at the same time, appreciate some of the great progress 

 already made in this rapidly growing field of astronomy. 



ACKNOWLEDGMENTS 



I am particularly grateful to Miss Frances W. Wright for the use 

 of table 1 and for her assistance in preparing the figures. Dr. Ger- 

 ald S. Hawkins has been very helpful in assisting in matters per- 

 taining to radio-meteor astronomy, and Mrs. Lyle Boyd and Dr. 

 Richard E. McCrosky have contributed to the final manuscript. 



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