364 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



The principal mass of the meteorite (30 pounds) is in the Amherst collection. In addition 

 Wulfing lists about 4 kgs., of which the Harvard collection has about one-half. 



BIBLIOGRAPHY. 



1. 1854: Willet. Description of meteoric iron from Putnam County, Georgia. Amer. Journ. Sci., 2d ser., vol. 



17, pp. 331-332. (Analysis by Shepard.) 



2. 1858-1862: von Reichenbach. No. 4, p. 638; No. 6, p. 448; No. 7, p. 552; No. 9, pp. 162, 174, 175, and 182; No. 



10, p. 359; No. 12, p. 457; No. 15, pp. 110, 113, 114, 124, and 128; No. 16, pp. 250, 261, and 262; No. 17, pp. 266 

 and 272; No. 18, pp. 478 and 484; No. 20, p. 622; and No. 21, pp. 5S5 and 5S9. 



3. 1863: Rose. Meteoriten, pp. 65 and 153. 



4. 1869: Meunier. Rechercb.es. Ann. Chim. Phys, 4th. ser., vol. 17, p. 35. 



5. 1885: Brezina. Wiener Sammlung, pp. '208-209 and 233. 



6. 1886: Huntington. Crystalline structure. Amer. Journ. Sci., 3d ser., vol. 32, p. 289. (Illustration of an etched 



plate.) 



7. 1893: Meunier. Revision des fers meteoriques, pp. 42—13. 



8. 1895: Brezina. Wiener Sammlung, p. 269. 



9. 1895.: Cohen. Meteoreisen-Studien IV. Ann. K. K. Naturhist. Hofmus. Wien, Bd. 10, pp. 82 and 85. 

 10. 1905: Cohen. Meteoritenkunde, Heft 3, pp. 343-345. 



Ranchito. See Bacubirito. 



RANCHO DE LA PLLA. 

 Durango, Mexico. 



Here also Durango of Partsch and Pila. 

 Latitude 24° 2' N., longitude 104° 36' W. 

 Iron. Medium octahedrite (Om), of Brezina. 

 Found 1882. 

 Weight, 46.5 kgs. (102.3 lbs.). 



The first account of the meteorite known to be from this locality was given by Hapke, 3 as 

 follows : 



In the spring of 1882 an iron was found by plowing in a field belonging to Rafael Brancho at Rancho de la Pila, 9 

 leagues east of Durango. The soil of this field contains considerable limestone. According to the view of the finder 

 and owner, the mass must have fallen since the last plowing of the field the year before, since, as it was only 25 or 30 

 centimeters deep, it could hardly have been overlooked in plowing. 



Hilmer Wilmanns, a merchant of Durango, with whom, when in Durango in 1877, I had talked regarding Mexican 

 meteorites, obtained a piece of this iron and sent it to his associate, Julius Hildebrand. The latter in 1882 sent me five 

 pieces of this iron, which together weighed 15 J grams and showed a well-marked crystalline structure. These pieces 

 were strongly magnetic, so that they were not only attracted by the magnet but themselves attracted iron filings. The 

 largest piece weighed 4 grams, which, like the others, had a dark crust, showed on cutting a hardness almost like that of 

 steel and a tin-white color, Since, also, on etching with moderately dilute nitric acid very beautiful Widmanstatten 

 figures were produced, the meteoric nature of the substance was considered certain. Herr Hildebrand accordingly 

 had sent on the whole mass, which arrived in Bremen in April. The meteorite was brought to the session of the acad- 

 emy of April, 1883, and compared with examples of other meteorites in the museum. By the efforts of Dr. W. O. Ficke, 

 a cast of the original was made for the mineralogical division of the museum. A second was made for the mining school 

 here and another for the Vienna Museum. 



The mass is of a prismatic-pyramidal shape, weighs 46.4 kilos, has a length of 30 centimeters, a breadth of 23$ 

 centimeters, and a height of 18 centimeters. A dark gray or brown shining crust envelops the mass except where 

 pieces have been broken off. The crust is shown by a stroke of the file to be very thin, supporting the view of the 

 finders that the iron had not lain very long in the earth. A file stroke shows further a tin-white co lor and a homogeneous 

 mass. The mass is penetrated by four parallel clefts which indicate that the foliated crystalline structure extends 

 into the interior. The surface of the mass shows many depressions in which, here and there, occur fine stria;. On one 

 side there is a round depression 1$ centimeters deep and 2 or 3 centimeters wide. On the opposite side there are two 

 of these, one large and one small, not so irregular as the first. The octahedral structure and the parallel foliated appear- 

 ance are well shown without etching and more strongly by etching. The foliated or banded structure characterized by 

 equilateral triangles and parallelograms shows fine parallel striations and hackly fracture, with single small crystals 

 projecting. On placing a polished and etched surface for a second time in a more concentrated acid the luster became 

 duller, and under the lens there could be distinguished parallel striae and granular portions. The crust in other places 

 was likewise dissolved by nitric acid. Here, also, the iron showed a tin-white color and granular portions which distin- 

 guished themselves from the more deeply attacked portions. The specific gravity of a piece weighing 4.25 grams, 

 almost without crust, was found to be 7.89, while that of a flat piece, almost entirely covered with crust, was found to 

 be 7.74. Dr. Janke obtained the following composition by analysis: 



Fe Ni Co P and C 



91.78 8.35 0.01 traces =100.14 



