318 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



Brezina 2 made the following observation in regard to the meteorite: 



A lumpy grain of the size of a nut which fell out during the cutting shows the imprint of the neighboring grains. 

 Upon the section surface are to be seen bent Neumann lines with somewhat bright yellow-colored porous crystals of 

 troilite. 



After acquisition of the principal part of the mass by the Vienna Museum the structure 

 was studied by Berwerth 3 with the following results : 



The analysis by Eakins led Linck to class Mount Joy as a hexahedrite, and when later Brezina, on a piece broken 

 from the surface, observed Neumann lines the meteorite was classed as a breccialike hexahedrite. For the purposes of 

 investigation and material for exchange the mass at the Vienna Museum was sawed in two parts in the direction of its 

 principal section, and the smaller part cut into corresponding smaller plates parallel with this section. The faces 

 obtained were so large and their character so remarkable that a complete investigation of the iron is in preparation; 

 here the only endeavor will be to correct the error regarding its structure which has crept into literature. The prepa- 

 ration of the faces for exhibition showed without question that Mount Joy belongs to the octahedral irons, and by its 

 very coarse structure should be placed among the last of the octahedral irons classed as having coarsest lamellae. The 

 general structure of Mount Joy is that of a coarse-grained mass, the coarse grains of which are intergrown and so elongated 

 with a certain regularity in one direction that the grains have a relatively short rodlike shape. From this shape and the 

 position of the grains arises an appearance of Widmanstiitten figures that is plain to the eye on a large section. The 

 fine crystalline structure of the single grains makes the figures more distinct, since the grains show a similar course of 

 Neumann lines, luster, and sheen. Contrary to the usual structure of octahedral irons with more compact band systems, 

 Mount Joy shows by reason of the more granular than lamellar formation a disconnected network of figures. A regular 

 inclusion of fine rhabdite is common to the grains. As regards the appearance of the etched surface the grains show two 

 characters. Along the section the course of the Neumann lines is shown plainly. In another part of the mass the 

 Neumann lines show only very weakly. This disguised appearance of the lines comes from the fact that the mass of the 

 grains has a composition of two fields, one of which is depressed and the other appears swollen on the etched surface. 

 This gives a spongy or shagreened appearance. In certain sections this etching of the fields is oriented . The two fields 

 show parallel strise and resemble the perthitic structure seen in twin feldspars. Of other components which occur in 

 the meteorite, troilite is present only in relatively small quantity in scattered nodules of medium size. Single nodules 

 contain white and lustrous crystalline inclusions. The troilite is regularly surrounded by a coating of schreibersite. 

 Schreibersite appears in larger skeletonlike crystals in the iron grains, also inclosing the troilite and interspersed between 

 the grains. Where the spaces between the grains are open wide and are cleft a dark oxidation product of iron taking a 

 good polish accompanies the schreibersite. These fillings are commonly regarded graphitic. Graphite seems, how- 

 ever, to be everywhere lacking. Where these oxidized interspersions are extensive there may also be seen an earthy 

 yellow silicate. To the above may be added the statement that the manner of the octahedral structure of Mount Joy, 

 showing its composition of great cubic crystalloids, requires a change in the present classification of iron meteorites. 

 Probably a revision of the so-called breccialike hoxahedrites will be required and its members put into the octahedrite 

 division. Thus Sao Julfao belongs, doubtless, to the octahedral irons. Further, it is indicated that all iron meteorites 

 possess an octahedral structure and that the meteorites of hexahedral structure which have fallen to our earth are 

 simply fragments of octahedral irons of very coarse structure. 



The mass is somewhat distributed but is cluefly in the possession of the Vienna Museum 

 (171,860 grams). 



BIBLIOGRAPHY. 



1. 1892: Howell. Description of the Mount Joy meteorite. Amer. Journ. Sci., 3d ser., vol. 44, pp. 415-416. 



(Illustrations and analysis by Eakins.) 



2. 1895: Brezina. Wiener Sammlung, p. 293. 



3. 1897: Berwerth. Ann. K. K. Naturhist. Hofmus. Wien, Bd. 12 (Not.), pp. 56-57. 



Mount Ouray. See Ute Pass. 



MOUNT VERNON. 



Christian County, Kentucky. 



Latitude 36° 55' N., longitude 87° 25' W. 



Ironstone. Brecciated pallasite (Pb), of Brezina. 



Found 1868; described 1903. 



Weight, 159.2 kgs. (351 lbs.) 



This meteorite was first described by Merrill, 1 as follows: 



The United States National Museum has recently come into possession of a heretofore undescribed meteorite 

 from the farm of Capt. S. T. Fruit, in Mount Vernon Township, about 7 miles northeast of Hopkinsville, in Christian 



