E. Cohen— Meteoric Iron from Soudan. 255 



not uncommon to find one or several especially deep cavities 

 at or near the apex of the anterior surface of an oriented 

 meteorite ; since, on the part of the surface farthest forward, 

 the incandescent and greatly compressed air has the greatest 

 erosive effect and can there produce the deepest cavities. 



It may further be concluded that this shield-shaped mass 

 with eccentric apex moved through the air inclined at an acute 

 angle to the direction of its motion, in which position the 

 direction of the projections and prominences on the back, as 

 well as the general drift-effect, are more readily brought into 

 accord. It has already been mentioned that the drift-effect 

 appears on both surfaces ; a fact which apparently has never 

 before been observed. However, on the breast it is much 

 more abundant as well as more regular, and is more sharply 

 defined on the broader part : while on the back it occurs dis- 

 tinctly only on the tapering end. Its occurrence on both faces, 

 and particularly its distribution, is intelligible to me only on 

 the assumption of an inclination of the meteorite to its path ; 

 for in a position either parallel or at right angles to the path, 

 the periphery must have encountered both the heating and air 

 erosion in an approximately like manner, and there could 

 scarcely have been such an unlike deformation. 



Because of the slenderness of the shield-shaped body, it is 

 highly probable that the entire mass was molten or at least 

 much softened, so that a considerable part was brushed off, and 

 the air, churned into eddies, could produce greater erosion and 

 abrasion than is usually the case. The result was that the 

 entire back, and the part of the breast to the rear, was covered 

 with closely crowded cavities and bowl-shaped depressions. 

 Only that part of the breast farthest forward suffered the 

 usual, almost evenly distributed melting, without any appre- 

 ciable splitting-off. Had the motion continued somewhat 

 longer, the deformation would apparently have advanced still 

 farther and possibly the entire remaining part of the shield- 

 shaped surface would have vanished. 



The total change of form must have been completed by a 

 time during which the velocity of the meteorite was still suffi- 

 cient for the formation of crest and drift-effect on the newly 

 made surfaces. It must, further, have been completed within 

 such a short period of time that a complete change of front, in 

 consequence of a change in the position of the center of grav- 

 ity, could not have taken place, since otherwise the drift-effect 

 must have been effaced. It is not impossible, however, that a 

 tilt occurred about an axis perpendicular to the length and 

 lying in the median plane. In the middle of the breast there 

 is an unusually deep cavity which, in every essential character, 

 is distinguished from all the other depressions. If this cavity 

 was produced in the same way as those on the back, then the 



