96 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



The etched sections show a strongly-marked octahedral structure with large figures; the plates of kamacite vary 

 much in size, ranging generally from 1 to 2 mm. in diameter, with an occasional broader one of from 2 to 4 mm., as 

 shown in the cut. The bands of tsenite are broad and quite prominent throughlout the mass, the plessite in many 

 places showing these bands crossing them in parallel layers (laphamite markings). This is shown particularly well 

 on some of the edges of the slices which have been oxidized, giving the tasnite a somewhat comb-like effect from their 

 relief above the weathered kamacite. 



No schreibersite was noticed by a macroscopical examination. The largest troilite nodule found in any of the sec- 

 tions is not over 2 mm. in diameter; others range from this down to the fraction of a mm. These latter were quite 

 abundant, as many as 16 of them being scattered over some of the slices. On the narrow end of three of the slices is a 

 fissure, entirely crossing the slice, filled with troilite. 



Some sections show that the oxidation of the surface had extended inward to the depth of 5 mm. in some places. 

 This readily accounts for the nonappearance of crust on the exterior surface of the mass, as well as the tendency in 

 some places to scale; also for the limonitic color of the whole. 



The examination of this iron by Professor Shepard was limited to two small pieces — barely an ounce in all — 

 which were from the outer surface, "and had the appearance of pure limonite." It was thus, as he suggests, difficult 

 to obtain either an exact analysis or exact specific gravity. This circumstance sufficiently accounts for the difference 

 between his analysis and the one lately made by Mr. J. M. Davison, of Rochester, New York, aa follows: 



Fe Ni Co P 



91.25 7.85 0.17* 0.10 =99.37 



Specific gravity, 7.68. 



Although the town of that name no longer exists, the mass was named Canyon City when Professor Shepard wrote 

 his paper and accordingly still retains the name. Mitchell's Atlas, edition of 1885, has Canyon City on the right, bank 

 of a branch of the Trinity River in the center of Trinity County, latitude 40° 55' N., longitude 123° 5' W. It is 

 satisfactory to be able thus to see rescued from the oblivion of uncertainty a meteorite which for more than a quarter 

 of a century has been known by name, yet absent and unknown in substance. 



The principal mass is in the Ward-Coonley collection. 



BIBLIOGRAPHY. 



1. 1885: Shepard. On Meteoric Iron from Trinity County, California; Amer. Journ. Sci., 3d ser., vol. 29, p. 469. 



2. 1895: Brezina. Wiener Sammlung, p. 342. 



3. 1897: Wulfing. Die Meteoriten in Sammlungen, p. 127. 



4. 1904: Ward. Amer. Journ. Sci., 4th ser., vol. 17, p. 383. 



CANYON DIABLO. 



Coconino County, Arizona. 



35° W N., 111° 7' W. 



Here also Arizona, 1891. 



Iron. Coarse octahedrite (Og) of Brezina ; Arva'itc (type 7) of Meunier. 



Found and described 1891. 



Total weight unknown. About 6,000 kgs. (6 tons) are preserved in collections. 



The first description of these meteorites was given by Foote 1 in 1891. He says: 



In the latter part of March, 1891, a prospector in Arizona informed the mining firm of N. B. Booth & Co., of Albu- 

 querque, New Mexico, that he had found a vein of metallic iron near Canon Diablo, sending them at the same time a 

 piece for assay, and stating that a car load could be taken from the surface and shipped with but little trouble. I there- 

 fore visited the locality in June, 1891, with a view to determining the probable nature of the find. * * * 



Nearly all the small fragments were found at a point about 10 miles southeast from Canon Diablo near the base of 

 a nearly circular elevation which is known locally as "crater mountain." (Sunset Knoll in the U. S. Geological 

 Survey.) This is 185 miles due north from Tucson, and about 250 miles west of Alberquerque. 



The elevation, according to the survey, rises 432 feet above the plain. Its center is occupied by a cavity nearly 

 three-quarters of a mile in diameter, the sides of which are so steep that animals are unable to escape from it. The 

 bottom seemed to be from 50 to 100 feet below the level of the surrounding plain. The rocks which form the rim are 

 of sandstone and limestone and are uplifted on all sides at an almost uniform angle of from 35 to 40 degrees. A careful 

 search, however, failed to reveal any lava, obsidian, or other volcanic products. It is impossible, therefore, to explain 

 the cause of this remarkable geological formation. 



About 2 miles from the point at the base of the crater in a nearly southeasterly direction, and almost exactly in a 

 line with the longest dimensions of the area over which the fragments were found, two large masses were discovered 

 within about 80 feet of each other. The area over which the small masses were scattered was about one-third of a mile 

 in length and 120 feet in its widest part. The longer dimensions extended northwest and southeast. 



The largest mass discovered weighed 201 pounds and had a somewhat flattened rectangular shape showing extra- 

 ordinarily large and deep pits, three of which passed entirely through the iron. * * * 



