MERRU.r. AND TASSIN] THE CANYON DIABLO METEORITES 2.0J 



There are yet to be considered in this connection the small pear- 

 shaped and oval balls of oxide which have been found by Mr. Bar- 

 ringer and others far out on the plain and wholly independent, so far 

 as locality is concerned, of either the shale ball just described or the 

 irons. These, as shown in text figure 48, are, as a rule, more 

 or less flattened and with surfaces much checked. Exteriorly they 

 are composed of platy iron oxide indistinguishable, either chem- 

 ically or physically, from that of the typical shale balls. These were 

 considered by Mr. Barringer as solidified drops of fused oxide 

 stripped off from the main mass by atmospheric friction. 1 



Several of these forms were found by the writer, and other more 

 typical forms were generously placed in his hands by Messrs. Barrin- 

 ger, Tilghman, and Holsinger. These have been cut in halves by a 

 diamond saw and have been found in their more solid parts to retain 

 still recognizable traces of the original crystalline structure of the 

 iron, and also still unoxidized particles of iron phosphides. But 

 it has been shoAvn by Berwerth 2 and Mr. Tassin's work in the Mu- 

 seum laboratory that the heating of meteoric iron, even at a tempera- 

 ture far below the point of fusion, completely changes its structure. 

 We are forced to conclude therefore that these forms are also prod- 

 ucts of terrestrial oxidation of small sulphur-chlorine-rich individ- 

 uals once buried in the soil, but in which the material, before ex- 

 posure by erosion, had so far adjusted itself to atmospheric condi- 

 tions that no subsecpient disintegration has taken place. 



There remains for the present to be discussed only the relationship 

 in origin between these chlorine-phosphorus-rich varieties and the 

 normal irons. 



As is well known, the fall is remarkable for the large number — 

 several thousand at least — of independent individuals which have 

 been found, and which show no evidence of atmospheric friction 

 such as is common to meteorites, and by which one is enabled to 

 judge of their orientation during the latter part of their flight 

 through the air. 



Such forms as those shown in pi. xxi, for instance, could not have 

 escaped the loss of some of their exposed edges and points had they, 

 unprotected, been subjected to any long frictional action. Yet these 

 are no exception to the rule, sharp angles prevailing, and the indi- 

 vidual irons showing further no torn nor broken edges such as to 

 suggest that they once formed portions of a larger mass. 



1 Such an origin would apparently have been considered as possible by 

 Lockyer. See his Meteoric Hypothesis, p. 69. 

 - Sitz. du Kaiserl. Akad. der Wiss., v. cxiv, 1905, p. 345. 



