278 U. S. BUREAU OF FISHERIES 



and eventually becomes rust pitted. Piping of pure lead is durable 

 and probably will come into greater use for the distribution of sea 

 water if it is protected from dents and supported against sagging. 

 Hard or chemical lead is more durable, but valves of this material 

 tend to become fixed or " frozen " and difficult to turn. Lead-lined 

 piping should be flanged at all connections and usually has lead-lined 

 valves, but such valves become Avorn with use. There probably is 

 no reason why the less-expensive galvanizecl-iron valve should not 

 be used and renewed when necessary. It is possible that valves of 

 vulcanized rubber could be used more cheaply in connection with 

 lead piping of the smaller sizes. 



Piping of hard lead with flanged joints will be used for all salt- 

 water lines in the aquarium planned for Chicago, this material 

 having given satisfactory service in the aquai-ium at Boston. The 

 valves will be of hard lead (8 per cent antimonial), with a few special 

 ball cocks of Government bronze. Heavy rubber gaskets will be 

 placed in all joints where bronze and lead meet. The new aquarium 

 in Bermuda is being fitted with piping of iron, glass lined, to be used 

 with hard-rubber cocks. The larger valves are of regulus metal, 

 much used in acid factories in England. The base of this metal is 

 lead. Overflows and drains will be of soft lead. 



The piping used in the aquarium at Philadelphia is of soft lead 

 in several sizes up to 5-inch, a 6-inch line extending over the filter 

 bed. The valves are of iron lined with bronze. This equipment 

 is reported to have given satisfactory service. Glazed earthenware 

 piping ought to come into more general use for drainage lines to 

 reservoir and sewer. If properly installed when the building is 

 under construction, it would be a permanent investment at the lowest 

 original cost. 



HEATERS FOR STORED SEA WATER 



As in northern latitudes it is necessary to keep tropical animals 

 in warm water during the winter months, means must be found 

 for maintaining the temperature to which they were accustomed in 

 nature. Stored sea water used as a closed circulation is wai-med by 

 a heating coil in one of the elevated distribution tanks. The gal- 

 vanized-iron coils originally used for this purpose in the New York 

 Aquarium were a source of trouble and expense, requiring occasional 

 removal for regalvanizing. The action of !*a water upon iron 

 appears to be more destructive when warm than when cold. The 

 heating coil being charged with steam, its galvanized surface did 

 not remain long in sound condition. A heating coil of bronze pipes, 

 which proved somewhat more durable, also failed to resist the action 

 of hot steam and salt water and soon became pitted and leaky, espe- 

 cially at the numerous threaded connections. In the effort to find a 

 more durable heater, a coil of chemical lead pipe was installed. 

 This heater lasted three years, and its use at least served to demon- 

 strate the value of lead for this purpose. 



The form of water heater finally adopted was a galvanized-iron 

 kitchen boiler, entirely incased in %-inch sheet lead and provided 

 with a 4-inch inlet and a 1-inch outlet, these connections being 

 incased similarlv in sheet lead. The heater lies on the bottom of a 



