Squhier—Peculiar Deposits on the Mississippi Bluffs. 261 
which so far as we can judge, the conditions for motion were 
as favorable as in situations now occupied by small active 
glaciers. 
The third, or northern area is too gentle in its reliefs to per¬ 
mit the formation of glaciers of the type here considered. It 
has been often studied and still receives much attention, with 
the purpose of locating the margins of the earlier drift sheets 
with greater precision. 
My own labor has been bestowed on the central area or more 
accurately, on a few localities along its northern margin. 
It was somewhat early in the eighties, I think in 1884, that 
the writer while spending a few days at Tomah (in Monroe 
county) was struck by the rather peculiar forms and the dis¬ 
tribution of the hills of chert gravel and sand in that vicinity. 
A year or two I’ater, in making an excavation near Trem¬ 
pealeau, he discovered a bowldery ridge near the lower end, and 
transverse to the axis of a small valley. 
For a few years thereafter, as opportunity offered, I sought 
for similar ridges in other valleys. Progress was slow, both 
on account of limited time and on account of the natural dif¬ 
ficulties of a search where the deposits studied have been so 
thoroughly concealed by later deposits as is the case with these. 
The results of the search were given in The Journal of 
Geology. 1 
Soon after, in seeking for deposits corresponding to lateral 
moraines, I discovered the features which form the more es¬ 
pecial topics of this article. They were described in the fol¬ 
lowing year. 2 
In the meantime I had revisited Tomah and in 1894 sub¬ 
mitted to Prof. Chamberlin an article descriptive of those 
features. He makes reference to it in a prefatory note attached 
to my first article giving his reasons for non-acceptance. 
In the presentation of his reasons he displays his customary 
fairness and moderation. 
In a third visit subsequent to this date I discovered features 
1 Vol. V, No. 8, P. 825, 1897. 
2 Journal of Geology, Vol. VI, No. 2, P. 182, 1898. 
