484 ■ PROCEEDINGS OF THE AMERICAN ACADEMY 



seems as if there were almost no limit to the fiue bands as seen with an 

 ordinary pocket lens. The bands, though small, exhibit all the fea- 

 tures of the coarser Widmanstattian figures. On the exterior of the 

 mass, small octahedral planes are distinctly visible, and a crack, shown 



Fig. 3. Tazewell, Claiborne County.* 



by the heavy line in the figure, following the octahedral cleavage, 

 nearly separates the mass into two portions. 



So far, the observations on octahedral irons do not differ materially 

 from what has been described in the papers already referred to. The 

 Widmanstattian figures are manifestly the evidence of a very perfect 

 crystallization, chiefly in the octahedral form ; and these octahedral 

 plates frequently may be readily separated, the successive depositions 

 of the plates producing a more or less jointed structure, similar to 

 that well known in cap-quartz. But this jointing must be clearly 

 distinguished from the octahedral cleavage or fracture above referred 

 to, which, as already stated, often passes directly through the plates. 

 Moreover, the perfection of the octahedral cleavage does not depend 

 upon the size and character of the Widmanstattian plates, many of 

 the irons which show the best figures affording no evidence of octa- 

 hedral cleavage, while some of the most compact break readily into 

 octahedrons. 



An example of the latter is shown in Fig. 4 from the Butler 

 (Bates Co.) iron, where the larger surface, drawn of its original size, 

 shows that the Widmanstattian figures are very fine, and not in broad, 

 distinct plates, while some of them are even microscopic; and yet 



* The illustrations of this paper were made by the Lewis Engraving Com- 

 pany, and although in the details they are faithful reproductions of the draw- 

 ings from which they were taken, yet the lines are all too heavy, and give the 

 idea of a much coarser structure than the meteorites actually present. This 

 is especially true of the above cut. 



