1905.] NATURAL SCIENCES OF PHILADELPHIA. 879 



several large specimens, one weighing over 200 pounds and others 

 over 100 pounds, having been found nearly a mile west of the crater, 

 and many small ones distributed around it, generally to the northeast, 

 north and northwest. This material is usually roughly globular or 

 oval in shape, the outside having been converted into hydrated oxide 

 of iron, while the interior is usually magnetic oxide of iron, showing 

 when broken open in nearly every instance the green hydroxide of 

 nickel. In a number of instances, however, these so-called "shale 

 balls" (I again adopt the local name) are found to contain a solid iron 

 center. We have some specimens where these iron centers probably 

 weigh as much as twenty to thirty pounds, the total weight of the 

 shale ball being considerably more than this. The magnetic oxide 

 which surrounds the iron center usually presents a more or less lami- 

 nated appearance, and I assume therefore that much of the so-called iron 

 shale found on the surface, as small flat or slightly curved pieces or 

 thick scale, from an inch to six inches in length and from one-sixteenth 

 inch to several inches in thickness, has resulted from the alteration of 

 shale balls, the iron in the great majority of the cases where these were 

 small or were detached from the meteor in the upper atmosphere 

 having had time to be entirely converted into magnetic oxide. There 

 is such a great similarity of appearance that this inference is to me 

 unavoidable, and I have recently noticed that the pieces of laminated 

 magnetic iron oxide are often grouped, especially where they have 

 been found on the outside plain some distance away from the crater, 

 as if a shale ball, or a piece of metallic iron which was once covered 

 by magnetic oxide of iron, had fallen on this spot and the magnetic 

 oxide of iron had been disintegrated, either by the force of the fall or 

 afterwards by ordinary atmospheric agencies.^ It is worthy of note 

 that the flat or slightly curved pieces of iron shale are found, like the 

 iron specimens, only on the surface or in the surface soil, and to date 

 at least have not been found admixed with the silica and rock fragments 

 on the outside of the rim, as the shale balls are frequently found. 



This brings me to attempt an explanation of tlie fact that these 

 so-called shale balls are to be found beneath the surface on the outside 

 of the rim, and admixed with the fragmentary material which was 

 certainly expelled from the crater, to a proven depth of tw^enty-seven 

 feet, and that the angular pieces of meteoric iron have been found up to 

 date only on the surface or in the shallow soil which overlies the rock 



* It may easily be, however, that pieces of metaUic iron were found at some 

 of these spots and taken away by the merchants who made a business of collecting 

 these specimens for sale to museums, etc. See footnote 9. 



