234 The American Geologist. April, 1896 
of the identifiable fragments. In this connection, I venture 
to repeat the suggestion that possibly the total movement <>r 
the ice has been overestimated, the more distant erratics hav- 
ing been, perhaps, transported in part by water and not 
wholly by the ice-sheet, each marked recession of the ice-sheet 
providing a series of glacial lakes and rivers alongits margin. 
Since writing out this paper, I have realized more distinctly 
than before that the points relating to the entire volume of 
the drift having been englacial during the active erosion of 
the bed-rock, the efficient protection afforded glaciated sur- 
faces by even a thin layer of till, and the consequent ruling 
out of drag as a mode of glacial transportation, have been 
previously stated by Mr. Upham.* But since I have approach- 
ed the subject in quite a different way, and there are still 
minor points of difference, this general acknowledgement is, 
perhaps, preferable to any attempt at quotation. 
FURTHER EXAMINATION OF THE FISHER 
METEORITE. 
By N. H. WiNCHELL, Minneapolis, Minn. 
From a coarsely powdered portion of this meteorite all 
grains were extracted which would adhere to a small magnet. 
This process removed also an equal bulk of other minerals 
which adhered to the metallic iron by reason of its interlock- 
ing contacts. 
The rest of the powder was placed in iodide of methyl hav- 
ing a specific gravity of 2.776, causing a separation into two 
portions. The heavier portion contained the residue of the 
iron, with still some interlocking grains, the troilite, olivine 
and the enstatite, and the lighter contained grains which 
could be divided into six groups. 
1. Some white, composite grains, though apparently homo- 
geneous in composition, which gave by a Boricky test abun- 
dant microlites of magnesia, or of lime and magnesia ; a bi- 
axial mineral. 
2. Isotropic, but wholly transparent, grains holding many in- 
clusions which render them sometimes almost opaque, or which 
polarize independently. These must be taken for glass. Some 
are black, derived probably from the crust, of which a small 
*Bull. Geol. Soc. Amer., v, 71-86, etc. 
