SEA-WATER SYSTEMS AT FRIDAY HARBOR LABORATORIES 



133 



FiGTJBE 2. — Receiving tank. 



C as it travels to the laboratory. The in- 

 sulation for the 2-inch line is shown in 

 figure 4. The remaining system was in- 

 stalled in 1959 of 3-inch polyethylene pip- 

 ing. This is virgin grade with a pressure 

 test of 75 pounds per square inch and ap- 

 proved as completely nontoxic by the Na- 

 tional Sanitation Foundation. This line 

 was not insulated but has been painted 

 with aluminum paint. Temperature 

 change in the water along this line in hot 

 weather may be as much as 2° C. 



Our aquariums and water tables in the 

 laboratories are of two types. In the old- 

 er systems they have been constructed from 



2-inch Douglas-fir, assembled in such fash- 

 ion that no metal of nails or screws is in 

 contact with the sea water. The wood 

 is untreated and becomes infested with 

 Bankia and Lirrynoria each season, but 

 these have been controlled by rotation of 

 use or intermittent use so that only a few 

 of the tables and aquariums have required 

 replacement in the jjeriod of almost 12 

 years. The aquariums are of simple de- 

 sign ; in most cases they are approximately 

 50 by 24 by 12 inches and the sea-water 

 tables are approximately 50 by 42 by 4 

 inches. They are supported on frames 

 constructed from li/2-inch iron pipe, 



