724 PROCEEDINGS OF THE AMERICAN ACADEMY. 



these iron masses have too low a magnetic susceptibility under the very 

 small values of magnetic force such as exist at low latitudes ; particu- 

 larly as the vertical component can alone be expected to yield indica- 

 tions of the presence of buried masses of iron. 



If further exploration is carried on it is possible that a system of in- 

 duction balance testing as proposed by me would be more fruitful, 

 though experiment alone could determine that fact. 



From many considerations which it would take too long to enumer- 

 ate it seems probable that if a large mass or cluster has buried itself at 

 this spot, it now exists under the southern and southwestern wall of 

 the crater and not near the center. It is a significant fact that the 

 rock layers exposed under the rim at the south show evidences of an 

 uplift of about 100 feet while still retaining their approximately hori- 

 zontal position. The depth of penetration is probably not more than 

 1200 feet, in which case the buried masses would lie upon or be slightly 

 embedded in the upper part of the underlying red sandstone layer, 

 which the bore holes put down near the center of the crater have shown 

 to be undisturbed there. 



In a recent report referring to Coon Butte, Bulletin 435 of 1910 of 

 the United States Geological Survey, Mr. N. H. Darton says : " After 

 an examination of the crater and consideration of all that has been 

 written, I believe we have no evidence adequate to explain its origin. 

 The hypothesis that it was caused by the impact of a meteor as urged 

 by Tilghman, Barringer, Fairchild, and Merrill is in accordance with 

 some of the features but does not accord with the all-important fact 

 that no meteor is present, as has been demonstrated by many bor- 

 ings." He forgets that only 28 test holes were put down and all near 

 the center of the crater and that such bodies rarely if ever fall verti- 

 cally. If a single large mass of 500 feet in diameter fell, to be sure of 

 finding it would demand the sinking of not less than 500 to 600 holes 

 if the whole crater is to be explored. He says further : " It is agreed 

 that if there was a meteor it must have been at least 500 feet in diame- 

 ter. The occurrence of a few tons of meteoric iron in the vicinity and 

 mingled with some of the debris on the rim and in the crater is an 

 enigma." He goes on to favor a suggestion by Gilbert that it was a 

 volcanic steam explosion that produced this crater, forgetting again 

 that the real key to the situation is the presence of the meteoric iron 

 in the way it is found to exist. 



A considerable expenditure of time and money has been made in 

 exploring this unique crater. This has been carried on largely by 

 Mr. D. M. Barringer, to whom belongs the credit of pointing out the 

 meteoric origin of the crater and collecting the proofs thereof. To him 



