120 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



Its fracture, judging from the piece that was partly cut and partly broken off before I got it, has the character of 

 that of a very soft kind of malleable iron, showing at the same time in its jagged fracture some regularity of 

 crystallization. 



Further studies of the meteorite are summed up by Cohen " as follows : 



By Reichenbach, 2 Charlotte is often mentioned as an example in his description of the trias. He notes well- 

 developed taenite, moderately dark plessite, fine combs, fine, regularly-developed figures with penetrating lamellae, 

 and delicate sheen like that of velvet. Further, he notes the small amount of accessory constitutents, the lack of 

 glanzeisen, and the occurrence of bronze-colored troilite occasionally in little cylinders or cones. At one place he 

 appears to include Charlotte among the irons with rust crust, since he, some pages further on, mentions that it has a 

 smooth, delicate, black crust, like Hraschina. Smith * states that the mass was taken from between the roots o'f a 

 great oak, and that the polished appearance of the surface remained after 40 years completely unchanged; also that 

 sections showed no alteration when exposed to the vapors of the laboratory. The nickel iron was soft and ductile, 

 free from schreibersite, and contained little cavities only to be noted under the lens. He observed no nodules of acces- 

 sory constituents. From the appearance of the surface he concluded that no complete fusion could have taken place, 

 except possibly on the edges and between the net-like ridges. The iron appeared to have been strongly heated but 

 not melted because the heat was quickly conducted to the interior of the mass. Specific gravity, 7.717. 



Analysis gave: 



Fe Ni Co Cu P S 



91.15 S.01 0.72 0.06 trace 0.00 =99.94 



Wright 4 by heating filings obtained 2.2 volume of gas of the following composition: 



H CO C0 2 N 

 71.4 15.3 13.3 0.0? =100.00 



According to Meunier, 8 Charlotte consists only of plessite and taenite, thus making Dick- 

 sonite. It differs in structure from Jewellite. 



Cohen's 9 own study of the meteorite is as follows : 



Although among the long straight lamellae about .17 mm. in breadth some lie isolated or only slightly grouped, 

 yet in general a strong grouping into broad bundles seems especially characteristic of Charlotte. The kamacite is 

 predominantly hatched, partly granular, the taenite evident. The octahedral structure shows considerable altera- 

 tion, especially on strong magnification. The fields are strongly developed, making up about one-half of the section. 

 In part they contain combs similar to the bands, and in part they contain plessite, which is either dull or shimmering. 

 Troilite occurs in the form of Reichenbach lamellae in the neighborhood of which a slight alteration in the structure 

 can be noticed. Clefts filled with ironglass run parallel to the lamellae. Finally, the very evident broad alteration 

 zone 3.2 to 3.4 mm. thick should be noted. All these characters are shown in a piece in the Vienna collection, which 

 from its form probably came from the thicker part of the meteorite. A plate from the Reichenbach collection appears 

 considerably different. There is an externally strong bending of the lamellae on one surface of the plate, which is 

 1.5 cm. thick, while on the parallel surface the bending is in part weak, but for the most part there is no deformation 

 at all. Taenite is strongly developed and shows, where the bending is strong, a zigzag course. The bands are long 

 and usually strongly grouped, quite free from granulation, and exceed in extent the fields. Most of the fields consist 

 of granular kamacite like the bands and an etched surface resembles that of a granular ataxite if one holds the section 

 so that the taenite is not reflected. Although the size of the grains appears under the lens quite uniform, under the 

 microscope it is seen to vary between .02 and .08 mm. The great number of the very irregular but sharply-bounded 

 grains furnish a similarly oriented sheen. Only a few fields consist of compact dark plessite or of such as is made up 

 of grains of medium size. There are no accessory constituents. A piece in the Tubingen collection which is bounded 

 on three sides of the natural surface and is about 25 mm. thick must have come from the pointed end of the pear- 

 shaped mass. Probably, however, this whole mass has suffered alterations which, on the thicker part of the meteorite, 

 were limited to the small outer zone. While an alteration zone is sharply defined, the octahedral structure is yet 

 plainly discernible. The surface is in part covered with a black branching crust, as Reichenbach describes. It is 

 so thin that one in most places can see lamellae. Here and there the crust either fails completely or is limited to small 

 spots which fill little depressions on the uneven surface. It does not give the impression that originally more crust 

 was present here. Charlotte plainly possesses no uniform covering with crust, and this other writers have stated. 



The meteorite is chiefly (2,359 grams) preserved in the Harvard University collection. 



BIBLIOGRAPHY. 



f 



1. 1845: Troost. Description of a mass of meteoric iron, which fell near Charlotte, Dickson County, Tennessee, in 



1835. Amer. Journ. Sci., 1st ser., vol. 49, pp. 337-340. 



2. 1858-1865. von Reichenbach. No. 4, pp. 638 and 640; No. 7, p. 562; No. 9, pp. 163, 174, 182; No. 10, p. 368; No. 



12, p. 457; No. 15, pp. 110, 113, 114, 124, 128; No. 16, pp. 250, 261; No. 17, pp. 266, 272; No. 18, pp. 478, 484, 

 487; No. 19, p. 154; No. 20, pp. 622, 629; No. 24, p. 226; No. 25, p. 612. 



3. 1875: Smith. A note in relation to the mass of meteoric iron that fell in Dickson County, Tennessee, in 1835. 



Amer. Journ. Sci., 3d ser., vol. 10, pp. 349-352. (Analysis.) 



