488 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 50 



and several petrographic and chemical analyses made, all of which 

 have been put at my disposal. Mr. Gilbert, in the systematic and con- 

 servative manner for which he is noted, considered the problem from 

 various standpoints, and particularly with reference to the theories of 

 its having been formed by the (i) "collision and penetration of a 

 stellar body"— i. e., by a meteorite, and (2) by steam explosion. In 

 the light of the evidence then available, Mr. Gilbert did not feel 

 justified in adopting the meteoric hypothesis, and, as the only avail- 

 able alternative, was forced to adopt the second mentioned above, 

 though those who know Mr. Gilbert thought to read in his report 

 a strong leaning toward the first mentioned, abandoned only because 

 not borne out, so far as he could see, by the facts. His failure to 

 recognize the tendency of Mr. Diller's studies is not so strange when 

 it is recalled that but a few fragments of the fused material had then 

 been found scattered over the plain, and with no certain connection 

 with the crater. It was not until more was discovered in the 

 work of prospecting, at a depth of several hundred feet below 

 the surface, that its full significance was realized. 



Though a matter of frequent discussion among those more or 

 less conversant with the facts, nothing of value relating to the sub- 

 ject appeared until 1905, when Messrs. D. M. Barringer and B. C. 

 Tilghman presented their results before the Philadelphia Academy of 

 Science. 1 Mr. Barringer described the crater and the character of 

 the ejectamenta in great detail, laying particular stress upon the 

 "silica," or pulverized sand grains (rock-flour), derived from the 

 sandstone. He reviewed the work of Gilbert and thought to prove 

 (p. 885) : (1) that a great meteor, wholly or in part metallic, fell 

 to the earth at this locality, and (2) that the crater was made by and 

 at the instant of time of the fall of this meteor. Mr. Tilgfhman dis- 



1 Coon Mountain and Its Crater, by Daniel Morean Barringer ; Coon Butte, 

 Arizona, by Benjamin Chew Tilghman. Proc. Acad. Nat. Science of Phila., 

 December, 1905. Issued March 1, 1906, pp. 861-914. It may be well to state 

 in this connection that Mr. Barringer is a well-known and successful mining 

 engineer and joint author with J. S. Adams of a work on Laws of Mines and 

 Mining in the United States. Mr. Tilghman, on the other hand, is a high 

 authority on velocity and impact of projectiles. These gentlemen, basing 

 their preliminary operations upon reports of Mr. S. J. Holsinger, took the 

 necessary steps to locate the "mountain" under the U. S. mining and land 

 laws, and proceeded to bore and sink shafts in and about the crater, with a 

 view of locating the fallen body, which they believed to lie there, desiring 

 to exploit it as a source of nickel, iron, and platinum. The conclusions re- 

 garding the origin of the crater, now arrived at, are based, so far as the pres- 

 ent writer is concerned, almost wholly upon results obtained in these mining 

 operations. 



