METEORITES OF NORTH AMERICA. 249 



It was found by one of the workmen, who gave it to Mr. John W. Gilbert, conductor of the construction train, 

 explaining that he had taken it out of a slanting hole within 5 feet of the track. It is now impossible to find the 

 exact locality, since the road was laid through new country, away from wagon roads or trails, and no particular atten- 

 tion was paid to the matter at the time. 



The specimen weighs 4,015 grams, and is of peculiar shape and appearance. Most of the meteoric irons which 

 have been collected and recorded appear to be angular fragments of larger original masses; but this one appears like 

 a thick scale or splinter, which must have been blown off from the spherical surface of a large body, since the entire 

 specimen is curved. Through the center runs quite a thick zone which gradually narrows down to sharp ridges on 

 all sides, these edges forming a continuous curved outline, with no jagged points or projections. It measures 26 cm. 

 long, 13 to 3.7 cm. wide, and 1.8 cm. thick. The exterior shows two utterly different surfaces; the convex side, 

 which must have formed the crust of the original mass, appears quite smooth except for a succession of small pittings, 

 with a little drop of chloride of iron in the center of each, making it rust rapidly, thus causing little scales to flake off 

 and thereby possibly producing the depressions. On the other hand, the concave side is characterized by a vesicular 

 structure not unlike certain furnace specimens, some of the cavities being 2 cm. across and nearly as deep. These 

 cavities seem to be distributed with more or less regularity in three parallel zones across the shorter dimensions of the 

 surface. These cavities appear to have no connection with the pittings of the surface. They seem to suggest an evo- 

 lution of gas from the material in the process of cooling, which may have been the cause of the splitting off of the 

 specimen from the original mass. 



Even the most malleable meteoric irons usually exhibit very striking peculiarities of cleavage parallel to certain 

 crystalline faces, large cleavage crystals being broken out from even such very compact irons as Bates County and 

 Coahuila. Indeed, the cleavage is sometimes relied upon as a means of distinguishing different meteoric irons when 

 other methods fail. But the fracture of this specimen exhibits no sign of cleavage. In fact the iron is so malleable 

 as to be readily rolled out into thin ribbons in the cold. Such extreme malleability and the peculiar fracture separate 

 this iron from all others. 



However, etching of the polished surface produces typical Widmannstatten figures, but showing plates not over 

 1 mm. thick, closely interlaced, frequently bent, and occasionally intersected by linear inclusions of troilite 2 or 3 

 cm. long. The figures closely resemble those of Oldham County, and are not unlike those of Obernkirchen, by being 

 so closely interlaced as to appear somewhat confused until carefully examined. On first etching the iron there was a 

 blackening of the surface, as in the case of steel, which gives, for the moment, prominence to the figures; the super- 

 ficial deposit is easily rubbed off, when the surface appears bright and shining but the figures indistinct. 



A preliminary analysis gave: 



Fe Ni P Cu 



90.24 9.75 0.05 Trace. =100.04 



Brezina 2 described the Vienna section as follows : 



This iron is noteworthy on account of its extreme softness, as well as for the zone of alteration surrounding the 

 entire mass, which extends some 12 mm. deep on the wedge-shaped border, while it is 3 mm, broad on the convex 

 front side and completely disappears on the nearly level rear side. The lamellae are 0.2 mm. in width, bands bent 

 and bunched; kamacite very finely hatched; fields few and small and of a dark-gray color. 



Cohen 3 described the structure as follows: 



The fragment described by Brezina appears to have come from the thicker portion of the meteorite; a few sec- 

 tions which I had occasion to investigate more accurately and which were apparently portions of the sharp edge were 

 different in character. 



The slightly bunched, nongranular bands were of very uneven length and of conspicuously irregular form; the 

 taenite ribbons were fine, but, especially after strong etching, distinctly prominent; the fields uniformly small and 

 subordinated to the bands. The extremely dull luster of the etching surface and the resemblance of the bands and 

 fields are very characteristic of this specimen; now the one and now the other appears the darker of these two, accord- 

 ing to the lighting. Even under the microscope both appear to be fine grained and are often only in a suitable light 

 distinguished from one another by the taenite seams; occasionally they are distinguished by the appearance in a few 

 fields of glistening flakes about 0.01 mm. in size. Under stronger magnification it becomes apparent that very small 

 fields, filled with compact, dark plessite, are present in considerable numbers. 



On the whole, it appears that the specimen which I examined belonged entirely to the alteration zone. 



Minor constituents are very scarce in these examples also. I did not find any schreibersite, and troilite only in 

 small crystals, 4 mm. long and 0.5 to 1 mm. thick, which are abruptly truncated at one end by a face and pointed at 

 the other, in consequence of which they appear hemimorphous, and very much resemble those previously described 

 from the Cape iron. Sometimes the crystals are insterected with daubreelite plates. 



The meteorite is distributed, the British Museum possessing 1,627 grams; Harvard, 1,570 

 grams. 



BIBLIOGRAPHY. 



1. 1890: HUNTINGTON. A new meteoric iron from Stutsman County, North Dakota. Proc. Amer. Acad. Arts and Sci., 



2d ser., vol. 17, pp. 229-232. 



2. 1895: BREZINA. Wiener Sammlung, p. 270. 



3. 1905: COHEN. Meteoritenkunde, Heft III, p. 370-372. 



