302 C. A. White on Drift phenomena in S.W. Iowa. 
of both sets being perfectly parallel with their fellows, distinct 
and straight. The surface of the rock had been ground level 
and smooth, removing all unevenness of the natural bedding 
surface. The directions of the strise were determined by a very 
good pocket compass. That of the coarser set (No. 1) was found 
to be 8. 20° E., and that of the finer set (No. 2) S. 51° H. No 
allowance was made in either case for the variation of the mag- 
netic needle, which the local surveyors calculate at about eleven 
degrees east of north. 
At an exposure of the same limestone one mile below Omaha, 
the capital of Nebraska, immediately upon the right bank o 
the Missouri river, and only some six or eight feet above the or- 
dinary stage of water, other scratches of a similar character were 
observed. They were found upon the upper surface of a 
ayer, which the workmen had exposed and were removing for 
building purposes. Here, however, there is but one set of 
seratches, their direction being S. 41° W. (set No. 3), not allow~ 
ing for variation of the magnetic needle. The surface of the 
rock is nearly or quite level, but the roughness of the natural 
_ bedding surface has not been entirely removed, yet the striz 
were so distinct that no difficulty was found in ascertaining their 
true direction. 
he drift at this locality is principally composed of a dark 
colored, stiff, clayey material, intermixed with sand, gravel and 
boulders, and varies from one foot to eight feet in thickness. 
Upon this rests the bluff formation as before described. The 
face of the bluff at the* locality where the latter observations 
were made is nearly at right angles with the direction of the 
D 
rie. 
Considering that the whole region surrounding these localities, 
and for a long distance to the northward of them, is an entirely 
in Mills county. — 
Since we see no evidence of the cotemporaneous existence of 
obstructions which might have deflected the current of a regular 
southerly moving glacier, and thus have produced the scratches 
