IOWA ACADEMY OF SCIENCES. H" 



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 openingv, cut with a file, to 

 permit a flow of gas when the opening at the end of the tube is 

 closed by the rising mersury. 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 1^ 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 lowan 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 lowan, 

 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 



