} 
| 9 
f LOCATION AND FIELD OF OPERATIONS 
The Illinois River near Havana has a maximum width of about five hundred 
‘feet at the lowest stage of water, and a maximum depth at that stage of ap- 
proximately ten feet. For a distance of about five miles, at the town and 
above and below, it runs along the foot of a steep sandy bank or bluff, rang- 
ing from forty to eighty feet in height, itself the edge of an extensive deposit 
of glacial sand extending with little interruption some seventy miles along 
the eastern side of the river, and perhaps a dozen or fifteen miles in width 
‘from east to west. The bottom of this bed of sand is not anywhere exposed 
near Havana and has not been reached, so far as I have learned, by any bor- 
ings in that vicinity. From the foot of the bluff, at or near the water’s edge, 
is a more or less general oozing of clear cold water sometimes flowing forth 
im springs of considerable size and sometimes forming small marshy tracts be- 
tween the river and the bluff. 
The opposite or western bank of the river here is of black earth, the border 
of an alluvial bottom three or four miles wide, in which are several ponds 
and lakes and through which Spoon River winds its way, entering the Illi- 
‘nois nearly opposite the town. At the upper end of this five mile stretch the 
river leaves the sandy bluff, having thence alluvial banks for some distance 
northward. The remnant of an old river bed continues upward, however, 
from this point along the bluff in the form of a narrow bay one and a half 
‘miles in length, the so-called Quiver Lake, open to the river below, and re- 
‘ceiving Quiver Creek at its upper end. This creek, largely formed by the 
drainage of a sandy tract to the east and north, empties into the broad and 
‘shallow head of the lake thr ough a muddy and weedy flat. Quiver Lake, like 
the river below, has a sandy bank and margin on the east, and a mud bank 
on the west. The natural drainage of the sand escapes in large quantities 
along the eastern side of this lake, keeping the shore constantly saturated 
with cold water, to a greater or less width according to the level of the lake, 
‘and modifying greatly, when the river is low, the character of the waters of 
the lake itself. A broad bay of this Quiver Lake extending to the west from 
near its middle, forms what is known as Dogfish Lake, with shores of black 
jalluvial earth all around. 
The other waters of the vicinity included in the system of Station opera- 
tions are Thompson’s Lake, a shallow body of water about five miles long by 
‘one mile wide, lying in the bottoms near the western bluff; Flag Lake, a 
shallow muddy pond or, more correctly, a marsh, about three miles in length, 
largely overgrown in summer with the elub- -rush, water-lily, and arrowleaf; 
and Phelps Lake, a small pond of dead water, three fourths of a mile in 
length, with almost no vegetation, in the midst of a densely wooded bottem- 
land. 
The field headquarters of the Station party, the summer location of the 
laboratory boat, was at the foot of Quiver Lake, against the sandy eastern 
bank. The top of the bluff is here wooded at the edge and for a variable dis- 
tance back with oak and hickory and ash and other common hard-wood 
upland trees. Cottonwoods, walnuts, locusts, coffee-trees, elms, and pecans of 
‘ 
a 
