84 ROCHESTER ACADEMY OF SCIENCE. 



composition of the iron than the numerous large masses of schreibersite 

 scattered through it. Some of these average from 30 to 40 mm. in 

 diameter, while others again occur in blades some 3 mm. in width 

 and 45 mm. in length. The Widmanstatten figures are sharp and 

 clear and of unusual size, picturing vividly the octahedral structure of 

 the iron. The kamacite plates are of unusual width, averaging from 

 3 to 4 m m. in width, and in one instance extending in an unbroken 

 line for 195 mm. The taenite films are comparatively small, but 

 are noticeable from their difference in color as they lie between the 

 kamacite plates. The iron is also characterised by almost the entire 

 absence of what is called plessite, the" Fiilleisen " of the German 

 chemists. 



There remains to notice a point in the structure or construction 

 of the iron mass which is of the highest interest, and is, in some 

 respects, quite unique. The section across the meteorite shows it to 

 belong to the limited group of brecciated siderites (see Plate X.), 

 and that its individual pieces, or soldered fragments, are by far the 

 largest which have ever been recorded. It will be noticed that the 

 surface of the section is crossed from one side to the other by a fissure. 

 And from a point somewhat beyond the middle of this fissure a branch 

 fissure leads off at right angles until it reaches the edge of the mass. 

 The two together make a letter Y, dividing the surface into three 

 areas. This fissure in parts of its course shows as a fine line with the 

 sides tightly closed up, and in other parts there is a filling of the 

 fissure with troilite in a broken vein varying in general width from i 

 to 3 mm., but expanding at these points to twice that width. That 

 this bifid fissure is a fracture of the original mass and that the troilite 

 has subsequently gathered in it, seems apparent, although that the 

 cracking and the filling shall have been closely allied in time is more 

 than likely, particularly when we keep in view the fact of the low 

 fusion point of the troilite. But the prominent and most novel feature 

 of this siderite section is still to come, and is as follows. We have 

 already mentioned the great length and distinctness of the kamacite 

 plates. They form on the surface lines of orientation showing the 

 structual growth of the ^rea. As, now, we notice the union of any 

 one of these areas with its two neighbors, we make the surprising 

 discovery that these surface lines do not match or correspond in 

 direction across the line of union — the fissure. (See Plate XI Fig i.) 

 In short, each area is quite distinct from each of the other two. The 

 appearance is as if the whole mass had originally been of continuous 



