Oct., 1907. Meteoric Studies II — Farrington 117 



and visible cracks are, however, all on the front side. That these 

 cracks are due to the necessity of a contracted exterior adapting 

 itself to a larger interior there can be no doubt. Whether, however, 

 their origin is to be ascribed to heating produced by the passage of the 

 meteorite through the atmosphere and consequent contraction upon 

 cooling, or to slower processes of weathering after its fall is not cer- 

 tain. Shrinkage cracks observed upon meteorite crusts at the time of 

 fall are usually of a finer pattern than those here seen and penetrate 

 little below the crust. The rusted character of the interior of this 

 meteorite shows that it has long been exposed to the weather. The 

 Dona Inez meteorite, which was exposed to similar climatic condi- 

 tions, is described by Howell* as being deeply penetrated by cracks. 

 The writer is therefore inclined to regard the cracks in this meteorite 

 as due to a slow hydration of the interior of the meteorite, such as 

 would be favored by an arid climate. In such a climate, water pene- 

 trating into the interior of the meteorite through minute interstices 

 would be held and cause hydration, while from the exterior it would 

 soon dry away. Minute cracks would thus become wedges which 

 would gradually split the meteorite open. The crust of the front side 

 while in general smooth, shows irregular patches and clots of fused 

 matter abundantly distributed over it. These patches are in general 

 darker than the surrounding crust. They are less than % millimeter 

 in thickness and a few millimeters broad. They grade, however, into 

 grains which scattered over the surface produce a stippled appear- 

 ance. Drift phenomena are lacking except, perhaps, for a slight 

 divergent arrangement of grains leading out from one or two of 

 the pits. 



The rear side of the meteorite as received showed a whitish'coating 

 in many portions. This effervesces and can be removed by acid and 

 is doubtless a carbonate of lime similar to that often observed 

 on meteorites which have been exposed for some length of time in arid 

 regions. When this coating is removed the true crust can be seen. 

 This is in part black and in part red, but always scoriaceous. It is 

 probable that the red color is due wholly to rusting and that the orig- 

 inal crust was black. The texture of the crust as seen under the lens 

 is quite uniform and minutely cellular throughout. Minute ridges 

 and hollows and partially opened blebs indicate fusion with the pro- 

 duction of gas bubbles. This crust shows a tendency to flake off as a 

 unit when struck with a hammer. It thus has the characters of Bre- 

 zina's "bark crust. " The pittings of this surface are broad, shallow, 

 saucer-shaped and confluent. Their diameters average about one 

 ♦Proc. Rochester Acad. Sc, 1890, Vol. 1, p. 93. 



