50 Howell — Description of the Williamstown Meteorite. 



right angles, these broader bands are cut at an angle of 60° or 

 70°, which would seem to show that in reality they are no 

 thicker than the others. Unfortunately our cut shows these 

 bands but faintly. 



Troilite seeraes to be pretty generally distributed through 

 the mass, but mostly in very small grains, although the cuttings 

 revealed one nodule f inches in diameter and two others of 

 about |- inch each. The total amount of this mineral, however, 

 is small, as might have been inferred from the specific gravity, 

 and the general smoothness of the surface. 



I am indebted to Mr. Wirt Tassin of the U. S. National 

 Museum for a chemical analysis of this iron and some notes 

 on its structure as follows : 



The structure of the etched face is octahedral. The three 

 alloys — kamacite, tsenite and plessite — are present. The kama- 

 cite bands are of average length, and the lamellae vary in 

 width from 0*5 to l*5 mm . The tsenite bands are of capillary size 

 and are often irregular in trend and distribution. Occasionally 

 the fairly uniform crystalline structure is interrupted by broad 

 irregular bands which have a length about twice that of their 

 width. Here and there are nodules of troilite, .some of which 

 enclose carbonaceous matter. These troilite nodules are 

 usually bounded by a thin line of schreibersite. The material 

 available for analysis gave : — 



Fe .-- 91-54 



Ni 7-26 



Co 0-52 



Cu 003 



O 0-05 



P 0-12 



S 0-17 



C 0-004 



Si '.'. trace 



99-694 



