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THE BALD EAGLE METEORITE

This interesting siderite has been loaned to me for examination and cutting by Prof. Wm. G. Owens, of the Bucknell University, Lewisburg, Pa. Prof. Owens read a paper upon the specimen before the Chemical Society of the University, and this was, the following year (1892), published in Vol. 43 of the American Journal of Science. From this article of Prof. Owen's I take my facts as to the finding of the mass.

Bald Eagle Mountain, on the east side of which the meteorite was found, is seven miles south of Williamsport, Pa. The mountain comes down to the edge of the Susquehanna river, and on the border of the latter runs the Philadelphia and Erie Railroad. Numerous transverse depressions occur here in the mountain-side, some of which are filled with loose blocks of sandstone, large and small.

"It was in one of these depressions, several hundred feet from the railroad track, that on or about Sept. 25, 1891, some Italians, while getting out stones for a stone-crusher, found in a bed of loose stones, about two meters deep, something which resembled a stone in appearance. It was covered with a fungus growth, as were the stones, but when picked up attracted the laborer's attention on account of its weight. He showed it to the Superintendent who tried to break it, and failing attempted to cut it with a cold chisel, when it proved to be soft iron. When several weeks later the owner of the crusher, Mr. George S. Matlock, came to the works it was given to him, and he, realizing its value, presented it to this university. It weighs 3.3 Kilos. (7 lbs. 1 oz.) In shape it resembles in general outline, a human foot. (Fig. 2, plate VIII.) The flat face, corresponding to the sole, measures 16.6 cm. (6 1/2 inches) long, and 8 cm. (3 1/8 inches) wide at the broadest place. From the extremity of the heel it projects upward 14 cm. (5 1/2 inches), ending in a point. The surface is covered with a reddish brown iron rust. This easily scales off in many places, and at several points this covering is so thin that the bright metal shines through. It is pitted quite deeply in some places, and very irregular in outline. * * * * * Its specific gravity is 7.06. It is quite soft compared with ordinary wrought iron. Chemical analysis gave Fe 91.36; Ni 7.56; Co. 0.70; PO .09; SO .06; Si. trace,= 99.77.

Nothing is known as to the time of its fall, though as it was found covered by several feet of stones which have not been moved sensibly since the Susquehanna valley has been inhabited by white men, it could not have been recent. As far as can be learned, this is the only specimen of the fall which has been found."

It has seemed to be desirable to add to this description by Prof. Owens a view of this most interesting iron. The picture (Fig. 2, plate VIII) is a half-tone taken from a photograph of the mass before cutting. Its resemblance to a human foot is very striking, despite the many rough notches and depressions which cover the surface. But few of these depressions are well defined pittings, seeming rather to be fractuosites, caused by the violent tearing of the iron from a parent mass, and the sharpness of the angles and crests reduced by the attrition to which the whole mass has been subjected. A portion only of the surface, all the upper part of the ankle, has a well smoothed surface, with a fine granulation akin to a skin or crust. On the back, above the heel, are two sharp depressions, one round and 3/8 of an inch in depth and in diameter, the other, half as deep, a paralellogram 3/4 of an inch long and 1/3 inch wide. Both of these have vertical walls, and show clearly as cavities which have once been filled with softer matter, probably troilite nodules, which have since been eroded or decomposed away. On the top of the front part of the foot is a deep cavity, due to the folds in the iron, which passes nearly through to the sole. The sole itself is very flat, which has allowed a thin slice, 1/4 of an inch thick and weighing 300 grammes, to be cut off, of same width from toe to heel, and like thickness throughout, like the sole of a shoe. The polished section is quickly etched by the use of dilute nitric acid, and the Widmanstatten figures produced are both sharp and peculiar. (Fig. 3, plate VIII.) The iron is typically octahedral. The etched surface is composed mainly of short kamacite blades, with an average thickness of about 1 mm. and from 5 to 10 mm. in length. These depart from the ordinary rule defining the usual angular figures by being largely curved or snake-like in form, giving a pattern like that of floss or tangled yarn. Many of these kamacite blades are club-shaped (rounded on both ends) as in the Augusta Co., Va., iron. The patches of plessite are minute, sometimes showing clearly the alternate layers of taenite and kamacite. The taenite plates lying between the kamacite blades are very narrow, but stand out in prominent relief on the etched surface, and are faintly distinguishable by their bronze yellow color from the tin-white kamacite.

Two fissures, each about 25 mm. in length and averaging from 1 to 2 mm. in width, cross the sole diagonally, and are filled with troilite. No rounded nodules of this mineral were to be seen in the section made. Several patches of schreibersite, rudely representing cuneiform characters, are scattered throughout the etched surface. These are brighter and with denser surface than the troilite, the latter being granular and less lustrous. But the main peculiarity of this iron is the extremely winding, vermiform assembling of the kamacite plates, to which we have already referred. In this respect the Bald Eagle iron is quite unique.

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