TROPICAL AQUARIA 



73 



and prevents the fish from leaping out, at which many of them are 

 extremely expert. Failure to replace covers has caused the loss of many 

 prized fishes. They will not suffocate if glass is down close. 



If one is not blessed with a heated greenhouse or a room of warm, 

 even temperature, artificial heating becomes necessary. There are several 

 devices which accomplish this purpose, but only a few are satisfactory. 



Fig. 54 



Fig. 55 



Fig. 56 



Fig. 57 



Fig. 58 

 TvrES OF Heating Methods 



Fig. 59 



In general those are to be avoided which concentrate the heat on a small 

 portion of the aquarium water. This action drives out oxygen and other 

 life-giving qualities and also produces uneven temperature for the fish to 



