GLACIAL GEOLOGY 
419 
now far away. But the later visitors in the field should move 
cautiously before making such sweeping disparagements on the 
integrity of the observations of the high-minded and keen investi¬ 
gators who have gone before — purest spirits that ever tarried in 
Iowa State. 
In the forty years^ that have elapsed since McGee examined 
these road-cuttings many changes of course take place. Repeated 
grading, hill-side erosion, and general weathering combine speedily 
to obliterate the freshness of the first exposures. With the original 
descriptions it is difficult to reconcile them with exposure features 
at any later time. Lees never saw the exact sections which McGee 
protrayed. He was never able to do more than brouse over the 
same general region. And now recent extensive grading and 
extension of the Capitol grounds completely obliterates the old 
outcrops without revealing anything new. Unless one knew just 
where McGee’s original exposures were it would now be exceed¬ 
ingly difficult to relocate them. The fact that the older drift in 
the locality was deposited on a very uneven surface, with the 
underlying Carbonic shales often bared, enables the loess to rest 
sometimes on the one and sometimes on the other. On Capitol 
Hill such diverse contrasts occur frequently every hundred feet 
or so. 
At the date when Lees says that he examined the drift features 
on Capitol Hill they were so very poorly preserved that it is 
doubtful whether any of McGee’s critical sections could be seen 
to advantage much less satisfactorily either varified, or disproved. 
In earlier days I repeatedly visited the sections and collected fossils 
from all of these original exposures, when they were still fresh 
and in much the same condition as when McGee left them, and I 
can unqualifiedly testify as to the accuracy of his statements down 
to the minutest particular. This is also the expressed opinion 
of Calvin, Bain, Leonard, Spencer, Todd, Shimek, and others 
who viewed and discussed the sections before they had become so 
badly weathered and covered as to be almost unrecognizable. 
The poor or obliterated condition in which Lees finds the sec¬ 
tions, the partial peep at them which is allowed him, and the cir¬ 
cumstance that in so short a distance away exposures occur which 
2 Am. Jour. Sci.. (2), Vol. XXIV, p. 202, 1882. 
