134 



ROBERT L. FERNALD 



Figure 3. — Pyrex stopcock. 



welded in the appropriate design and 

 painted with rustproof paint (see fig. 5) . 



In the research laboratory recently com- 

 pleted, the aquariums and sea- water tables 

 have %-inch plexiglass sides and bottoms. 

 The tanks are supported on the pipe 

 frames on sheets of %-inch marine ply- 

 wood to avoid putting stress on the plexi- 

 glass. In addition, the new research build- 

 ing is equipped with a few reinforced-con- 

 crete tanks of different sizes and shapes. 

 Among the more useful are two circular 

 tanks 8 feet in diameter and 30 inches 

 deep. These are especially well adapted 

 for the maintenance of more rapidly mov- 



ing and swimming animals such as squid 

 and fish. Another concrete tank is a large 

 rectangle, 5 by 10 feet, varying in depth 

 from 1 to 3 feet. Other concrete tanks are 

 developed as double-deck water tables, 3 

 feet wide, 8 inches deep, and as long as 

 14 feet, with 17 inches' clearance between 

 the two tanks. 



In carefully conducted tests to deter- 

 mine the suitability of a wide variety of 

 plastics and substitute piping materials 

 for use in sea-water systems, we found 

 nothing more satisfactory than Pyrex 

 glass. Many materials proved quite un- 

 satisfactory and some essentially useless. 



