Meteorite Collection — Handbook and Catalogue. 21 



ures, /'. e. made up of narrower bands, can be seen in the Lion River 

 (62), Smith's Mt., N.C. (85), Bear Creek (89), Bates Co., Mo. (96) 

 and Hamilton Co., Texas (131), irons. 



The finer lines were regarded by Neumann as indicating an 

 essentially different structure from that shown by the Widmanstatten 

 figures and they are hence often called Neumann lines. 



As pointed out by Huntington,* however, every gradation can 

 be traced between the coarsest Widmanstatten figures and finest 

 Neumann lines, so that there is no reason for regarding them as dis- 

 tinct. In Huntington's view the coarser figures characterize the irons 

 in which there was a large amount of foreign matter to be elimi- 

 nated, the finer, the purer irons. The former moreover tend to an 

 octahedral structure, the latter, a cubic. 



Most authorities agree that the crystalline structure exhibited in 

 the meteoric irons indicates that they remained for a long time in a 

 fused or viscous state from which they cooled but slowly. 



Thus Tschermakf states that "the greater number of meteoric 

 irons exhibit a structure which indicates that each formed part of a 

 large mass possessing similar crystalline characters and the formation 

 of such large masses presupposes long intervals of time for tranquil 

 crystallization at a uniform temperature". SorbyJ also regards "the 

 Widmanstatten figures as the result of such a complete separation 

 of the constituents and perfect crystallization as can occur only when 

 the process takes place slowly and gradually. They appear to me to 

 show that the mass was kept for a long time at a heat just below the 

 point of fusion. " 



Further evidence of this is seen in the curved or bent plates con- 

 tained in some meteoric irons (Stutsman Co., 126), which were 

 probably formed as true planes but, remaining viscous longer than 

 other portions of the mass, suffered subsequent distortion. 



It should be noted that there are some irons usually regarded as 

 meteoric, which exhibit no trace of the Widmanstatten figures 

 (Chesterville, 56, Allen Co., 92, Maverick Co., 113). Others show 

 only a coarse, irregular network of markings (Seelasgen, 375, Puquois, 

 124, Silver Crown, 130). 



These may be considered as having been formed under somewhat 

 different conditions from those which prevailed in the formation of 

 other meteoric irons, or it may be questioned whether they are not of 

 terrestrial origin. 



♦Proc. Am. Acad. Arts and Sciences, May, i836, also Am. J. Sc, 3rd ser.. Vol. 32, p. 284. 

 tSitz. Wien. Akad., 1875, Bd. 71, pp. 661-673. 

 JNature, 1877, Vol. 15, p. 498. 



