THE INCUBATOR. 



137 



of heat and consequent fluctuations in temperature. In 

 the top of the chamber is a small opening through 

 which a thermometer projects into its interior. At 

 either corner, leading into the space containing the 

 water, are other openings for the reception of another 



Fig. 28. 



Incubator used In bacteriological work. 



thermometer and a thermo- regulator, and for refilling 

 the apparatus as the water evaporates. On the side is 

 a water-gauge for showing the level of the water between 



