IOWA ACADEMY OP SCIENCES. 
117 
each ten inches high and the top one eleven inches, the shelves 
being of one-fourth inch mesh galvanized iron wire netting. 
In the top compartment is the heat regulator, which consists 
of a 100 cc. flask for a bulb, and a one-fourth inch glass tube 
with a double bend, to contain liquid and to receive the gas. 
One end of the tube passes through a rubber stopper into the 
flask, while the other end receives a smaller tube, reaching 
down toward the mercury in the lower curve. On the side 
of the small tube is a capillary opening, cut with a file, to 
permit a flow of gas when the opening at the end of the tube is 
closed by the rising mercury. The liquid used in the bulb is a 
solution of calcium chloride, and in the bend of the tube is 
mercury. Other liquids may be used. 
The incubator was used last spring in class work in bacter- 
iology and gave good satisfaction. The greatest variation in 
temperature observed was not over 2^ degrees, and this only 
when the room became quite cold. The usual variation was 
not over degrees. Experiment shows that the temperature 
in the incubator increases from the lowest shelf to the highest, 
if the burner is placed under the opening of the pipe, or near 
it; but if the burner is near the front of the incubator, or under 
the opening in the center, the temperature is nearly equable 
throughout. 
BURIED LOESS IN STORY COUNTY. 
BY S. W. BEYER. 
The Iowan till is not known to be present in Story county. 
The trend of its southwestern margin which crosses Johnson, 
Iowa, Tama and Marshall into Hardin county, if maintained 
with reasonable constancy, would carry it safely beyond the 
confines of the county. The loess, the silty apron of the Iowan, 
although suspected to be present on account of the geographic 
position of the area and of certain topographic contours which 
are decidedly loess-like in character, was not recognized cer- 
tainly until during the present field season. The loess is now 
known to appear at numerous points along the flanks of the 
deeper cuts in Indian Creek and Collins townships, in the 
