THE INCUBATOR. 



121 



asbestos boards or thick felt, to prevent radiation of heat 

 and consequent fluctuations in temperature. In the top 

 of the chamber is a small opening through which a 



FIG. 27. 



Incubator used in bacteriological work. 



thermometer projects into its interior. At either corner, 

 leading into the space containing the water, are other 

 openings for the reception of another thermometer and 

 a thermo-regulator, and for refilling the apparatus as 

 the water evaporates. On the side is a water-gauge for 



