206 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



FORT PIERRE. 



Stanley County, South Dakota. 



Here also Nebraska. • 



Latitude 44° 21' N., longitude 100° 2CC W. 



Iron. Medium octahedrite (Om), of Brezina; Caillite (type 18), of Meunier. 



Found 1856?; sent to St. Louis 1857; mentioned 1858; described 1860. 



Weight, 16 kgs. (35 lbs.). 



The first mention of this meteorite is found in the Transactions of the Academy of Science 

 of St. Louis. 1 Chouteau is there said to have presented to the Academy a mass of meteoric 

 iron of 35 pounds weight found in Nebraska Territory about 20 miles from Fort Pierre. A 

 further account was given later by Holmes 2 as follows : 



This mass of iron was brought down from Fort Pierre to St. Louis by the American Fur Company's steamer in 

 charge of Mr. C. P. Chouteau, in 1857, and by him presented to the Academy, in the spring of 1858. It was said to 

 have been found in Nebraska Territory, at a point about 20 miles from Fort Pierre, which is situated on the right bank 

 of the Missouri River, in latitude 44° 19' N., longitude 100° 26' W., nearly. The weight of it when found was 35 

 pounds; when presented to the Academy, it weighed 30.5 pounds, a piece having been previously cut off as a speci- 

 men. Since that time, two other specimens, weighing together about 3.5 pounds, had been cut off at the same end 

 and presented by the Academy, the one to Prof. C. U. Shepard, of New Haven, and the other to the Imperial Min- 

 eralogical Museum of Vienna. 



In form and shape it was irregular, somewhat flattened, with rounded corners and obtuse edges. On three sides 

 the surface was covered with irregular depressions or indentations. One of these sides is a concave surface filled with 

 these indentations, or wavy depressions. The color of the outside was brownish black; the inside (cut or fracture) 

 had the light gray metallic color of iron; and the cut surface showed flaws in the mass. The outside color was merely 

 superficial, and there had been but a slight degree of oxidation of the surface. Prof. C. U. Shepard, who had an oppor- 

 tunity of examining it, thought it could not have been upon our earth more than four or five years. The iron was soft 

 under the cutting tool, and the workmen engaged upon it, as well as Mr. Albert Dwelle, foreman of the Fulton Foun- 

 dry, whose attention had been called to it, at the time, had been well satisfied that they observed a distinct smell of 

 something like camphor in the process of cutting. 



The length was 11 inches, breadth 4.6 inches; thickness at one end 6 inches, at the other, 3 inches, tapering 

 suddenly to an obtuse edge. 



Analysis by H. A. Prout gave the following: 



Fe Ni Mg Ca S 



942.88 71.85 6.50 3.50 trace =1024.73 



Prout also states that the nickel is entirely free from traces of cobalt, chromium, manganese, or other elements 

 eometimes found in these masses. 



Shepard, 3 under the title of the Nebraska iron, gave an account as follows: 



This mass was found near the Missouri River, between Council Bluffs and Fort Union. It originally weighed 

 about 35 pounds, but is reduced to 29. Its shape was an oblong, compressed oval, not unlike that of the Chesterville, 

 South Carolina, iron mass, which has been compared by me to a thick, blunt edged fresh water clam ( Vnio). 



Its surface is as black and smooth as that of the Braunau iron, from which, however, it differs in being more even 

 and smooth, though not destitute of the usual indentations belonging to meteorites, but these are by no mea,ns uni- 

 form in their occurrence over the entire surface. The crust is everywhere extremely thin, amounting to scarcely 

 more than a mere varnish; and, what is very remarkable, is often insufficient to hide the Widmannstatten figures. 



The lines are not equally displayed throughout, and indeed generally require a single lens in order to be dis- 

 tinctly seen. Nor have they the same beautiful regularity as when obtained by etching upon a polished surface 

 from the interior. They are, moreover, ciuiously knotted, so as to resemble under the microscope the blunted teeth 

 of a fine saw blade. The configuration upon the etched plates of this iron resemble that of the Texas mass, though 

 the bars are much more rectilinear, and in this respect approach nearer to the African irons from Namaqua Land and 

 Orange River. The fullest regularity of internal structure does not prevail, however, until some depth from the outer 

 surface or crust is reached . 



This iron is entirely free from earthy, plumbaginous, or pyritic matter. The character of the surface renders it 

 certain that this mass must be of very recent fall. 



Its specific gravity is 7.735. 



Haidinger 5 gave the following account of the piece which he received: 



I received a piece weighing 1 pound and had it cut through the largest diameter and both faces polished. One of 

 the remaining pieces, 1\ inches long, 2 inches wide and 10 lines thick, is bounded upon one side by this section surface, 

 upon the other is mostly bounded by the natural surface, which is fairly even between the rounded edges, and has 

 only very shallow pittings. 



