iv SCIENCE—ADVERTISEMENTS 
HEARSON INCUBATORS 
WITH HEARSON PATENT CAPSULE TEMPERATURE 
CONTROL FOR GAS, OIL AND ELECTRIC HEATING 
A large stock has just been received, all of which is 
available for immediate shipment 
No. 20740 Hearson Gas Heating Incubator, inside dimensions 15x15x18 inches. Price $120.60 
We have supplied several hundred Hearson Incubators to important U. S., State, City and 
Hospital bacteriological laboratories throughout the U.S. Their performance has been universally 
satisfactory and in view of this experience we are willing to recommend the Hearson patent capsule 
temperature control as being the most accurate and simple device for the uniform control of incu- 
bator temperature now on the market. 
_ We supply them in nine sizes for gas heating, six sizes for oil heating, six sizes for electric heat- 
ing and eight sizes for low temperature, and keep a stock on hand of the more popular sizes for im- 
mediate delivery. 
Complete descriptive pamphlet sent upon request 
ARTHUR H. THOMAS COMPANY 
IMPORTERS - DEALERS - EXPORTERS 
LABORATORY APPARATUS AND REAGENTS 
WEST WASHINGTON SQUARE PHILADELPHIA, U. S. A. 
