54 



BIOLOGICAL SURVEY OF 



The aquaria are carried on a long double-deck bench, 

 and if an aquarium, bucket, or a jar carried material there 

 was always fastened to the side, by a wooden clothespin, a 

 number showing where the material had come from so that 

 it might always be checked back to its original station. 



Fig. 20 Laboratory, view from land. 



The water for the aquaria is handled through a centrifugal 

 lead pump drawing water from the outside crib of the dock 

 and supplying it along the dock through a lead-lined pipe 

 to the large wooden tank. Running the water directly 

 through to the tank and then having it return to the labora- 

 tory relieves the pressure on the spigots and they can there- 

 fore be turned on with confidence that the amount of water 

 flowing through them will be constant instead of being forced 

 at times from the pump and fed at other times from the. 

 return. The capacity of the tank is such that all of the 

 spigots on the laboratory could be allowed to run for 15 

 hours without draining off all the water. This permits leav- 

 ing it overnight without danger and also prevents being- 

 caught with a low tide — a 10-foot tide has to be reckoned with 

 at times. 



