374 PROCEEDINGS OF THE ACADEMY OF [1893. 



plate of soft iron it made an impression alike visible to the eye and 

 sensible to the touch. These three physical proofs would seem to 

 warrant calling the object a tempered steel meteorite. 



How the metal became tempered can only be explained hypothe- 

 tieally. Meteorites, in their passage through the atmosphere, become 

 red-hot and if they fall into a pool of water or a deposit of snow or 

 ice they are quickly cooled. Should the chemical composition be 

 such as to form steel, the mass, under such conditions, becomes 

 hardened. On heating one of the granules to redness and allowing 

 it to cool slowly, its softness under the file-test conclusively demon- 

 strated that natural steel is similar to the artificial product. 

 The sharp-edged steel tool of a planing machine would doubtless 

 have been broken by contact with the hard mass while in motion. 



The extreme hardness might be supposed to indicate the presence 

 of diamonds, but that mineral is never found in any of these suspected 

 meteorites. The Widmanstatian figures are small, as might be 

 expected when we consider the quick cooling ; only small crystals 

 forming under such circumstances. 



Upon magnifying the figures about twenty diameters, by 

 reflected light, the rectangular figures of the cube forming at times 

 rod-shaped elongations and also triangular outlines of the octahe- 

 dron, sometimes with sharply defined cleavage lines, were observed 

 together with very acute triangles, which may belong to the tetra- 

 hexahedron. 



A second surface on the same specimen, nearly at right angles to 

 the first, was ground with greater ease on a corundum wheel running 

 at great speed in order to determine whether the crystallization could 

 be recognized to better advantage, but without result, as the second 

 surface was no better than the first. That the structure might be 

 presented to better advantage, the polished, etched surface was 

 magnified about three diameters and photographed. (Plate IX, fig. 

 1). The lines, although faint, are apparent and, generally, the 

 angular outlines of crystal forms can be easily traced. The half 

 tones in the picture are the portions of the surface eaten out by the 

 nitric acid. The shining surfaces are the reflections of the nickel 

 steel and the dark pits are the crude untouched material. Cleavage 

 lines predominate throughout the whole surface. A few of the 

 regular outlines were drawn and appear in figure 2. The most 

 common outline appears in figure 4. The dark crystalline figure 

 was etched out by the acid treatment, as was also the larger dark 



