416 PROCEEDINGS OF THE NATIONAL MUSEUM vol.90 



This meteorite when only a few miles above om' earth was very 

 large, probably weighing a hundred tons or more, and to suppose that 

 the entire mass was composed of the same minerals and in the same 

 proportions as found in the smaller specimen would be a broad assump- 

 tion. Very likely there were no large concentrations of metal in the 

 mass, because, if so, a sizable chunk of metal should have survived 

 the flight to the earth and made a scar on the countryside that would 

 have been detected by this time. 



This is the first stone and the sixth meteorite reported from Penn- 

 sylvania. Stony meteorites are very rare in the States surrounding 

 Pennsylvania. Ohio is credited with 2, New York only 3, Maryland 

 2, New Jersey 1, and West Virginia none. 



No attempt has been made to determine the age of this meteorite, 

 because the sample is small and the results from such a study are not 

 highly accurate. Neither have we tried to determine whether the 

 Chicora meteorite is magnetically polarized, to indicate solidification 

 in a magnetic field. In fact, there are a great many questions that 

 should be put to these celestial visitors from space, and thereby gradu- 

 ally enough evidence will be accumulated not only to classify the 

 different kinds but perhaps to reach some conclusion as to their source. 

 Had the hundred-ton mass of the Chicora meteorite reached the earth 

 it is difficult to imagine the havoc it would have produced. At any 

 rate, the people domiciled in Butler County, Pa., should be very 

 thankful that falling meteorites have such great difficulty in pene- 

 trating the thin layer of air immediately overhead. 



ACKNOWLEDGMENTS 



We are indebted to John L. Stewart, editor of the Washington, Pa., 

 Observer, for his efforts in locating for us observers in the extreme 

 south part of the terrain. 



In connection with the petrographic work, much valuable assistance 

 was given by Miss J. J. Glass, who made a careful optical study; 

 Prof. H. H. Hess, who also confirmed the optical examination; Dr. 

 L. G. Henbest, who made the microphotographs; Prof. S. J. Shand, 

 who prepared the thin section of the meteorite; and Dr. W. F. Foshag, 

 who offered many helpful suggestions. 



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