METEORITES OF NORTH AMERICA. 45 



81. 1890: EASTMAN. Met. Astron., p. 318, 322. 



22. 1890: BBEZINA. Oesterr. Zeitechr. f. Berg- u. Huttenw., Bd. 38, p. 358. 



23. 1891: COHEN 0. WETNSCHENK. Meteoreisen-Studien. Ann. K. K. Naturhist. Hofmus. Wien, Bd. 6, pp. 131, 



132, 142-143 (Analysis), and 160. 



24. 1892: COHEN. Meteoreisen-Studien. Ann. K. K. Naturhist. Hofmus. Wien, Bd. 7, pp. 147-148 (Analysis), and 162. 



25. 1893: MEUNIER. ReVision des fere m&ebriques, pp. 16 and 21. 



26. 1894: COHEN. Meteoritenkunde, Heft I, pp. 67, 68, 86, and 99. 



27. 1395: BRBZINA. Wiener Sammlung, p. 297. 



28. 1895: COHEN. Meteoreisen Studien IV. Ann. K. K. Naturhist. Hofmus. Wien, Bd. 10, pp. 83, 90, 91. 



29. 1900: COHEN. Meteoreisen-Studien X Ann. K. K. Naturhist. Hofmus. Wien, vol. 15, pp. 88-94. 



30. 1905: COHEN. Meteoritenkunde, Heft III, pp. 104-112. 



BACUBIRITO. 

 Sinaloa, Mexico. 

 Here also Ranchito. 



Latitude, 26 1' N.; longitude, 108 3' W. 

 Iron. Finest octahedride (Off) of Brezina. 

 Found 1863; mentioned 1876. 

 Estimated weight, 27 tons. 



The first mention of this mass was by Senor Mariano Barcena, 1 a Mexican scientist and 

 astronomer, in an article devoted to Mexican meteorites. He spoke of it simply as "an enormous 

 meteoric mass lately discovered in the state of Sinaloa." He stated that he could not remember 

 its exact dimensions but could assure the Academy that its length was more than 12 feet. The 

 mass is also mentioned by Castillo in his catalogue of Mexican meteorites. 3 But no one who 

 mentioned it claimed to have seen it and there was no definite description of the mass until 

 a personal investigation was made by Prof. Henry A. Ward* in the spring of 1902. 



He found the meteorite 7 miles due south from Bacubirito, a small but very old mining 

 town, situated on the Rio Sinaloa in latitude 26 X., longitude 107 W., at an elevation of 2,000 

 feet above sea level. It was near a little hamlet called Palmar de la Sepulveda. It was found 

 on a farm called Ranchito, which fills the narrow mountain valley or interval between two spurs 

 of the foothills, running nearly north and south. It lay in a corn field, close by the eastern 

 edge of this vale, where the level ground began to rise against the hillside. The valley and 

 the field were of black vegetable soil, some two yards in thickness. In this soil the meteorite 

 lay imbedded, its surface being but little below the general level of the field around it, but one 

 end projecting slightly above the ground. The other end was deeply imbedded in the soil, which 

 had never apparently been disturbed. 



On digging away the soil the meteorite was found to lie in a depression crushed into the 

 rock with absolutely no trace of soil between it and the part where the full weight of the mass 

 had fallen and lain. It would thus seem, according to Ward, that the meteorite had fallen 

 on the bare surface of the district at a period before the vegetable soil had begun to form. On 

 the other hand the mass appeared to be well preserved. It showed little oxidation, and the pit- 

 tings were clean and sharp-rimmed, thus seeming to point to a rather recent fall. 



The form suggested a ramus of the lower jaw of a mammal, but was quite irregular. The 

 extreme dimensions of the mass as given by Ward are: Length, 13 feet 1 inch; width, 6 feet 

 2 inches; thickness, 5 feet 4 inches. Owing to the irregularity of form the cubic contents 

 could be only roughly estimated. Ward estimates the weight at 50 tons, and regards it as 

 the largest meteoric mass in the world. 



In structure, according to Ward, the mass exhibits well-defined octahedral crystallization. 

 Fractured surfaces show crystallization plates with faces from 3 to 19 mm. in greatest diameter. 

 Many of these are covered with fine films of taenite, mostly of the characteristic bronze-yellow 

 color. Well-defined Widmannstatten figures of fine pattern are brought out by etching. The 

 kamacite plates are but a fraction of a millimeter in diameter. Some of these blades appear 

 to be of double that thickness, but the glass shows these to consist of several single blades. There 

 is thus a strong development of plessite. The rhombic figures on the etched face average from 



