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such a pond, the only one that now seems possible to 

 biologists and engineers alike, is to build the concrete tank 

 above the ground on the garden site close to the engine- 

 house. Here there is space for a pond 60 feet by 20 feet, 

 and 10 feet deep, which would have a capacity of about 

 75,000 gallons. Our present pumps are capable of supply- 

 ing about 2,500 gallons per hour, and the tides allow of 

 pumping for about 4 hours out of 12, two and a half hours 

 before and one and a half hours after high water. When 

 the pond is full it would be possible to change at least 

 one-seventh of the whole contents each tide, and in the 

 intervals between the periods of pumping this seventh 

 part, over 10,000 gallons, would be used for working the 

 apparatus in the tank room. It is most desirable that 

 permission to proceed with the erection of the required 

 pond be obtained from the Board of Trade with as little 

 delay as possible. Such a pond could be made available 

 for various useful purposes, such as fish spawning, lobster 

 hatching and rearing, and oyster spatting and cultivation. 

 In the early spring over 600 mature fish could be accom- 

 modated, which should provide an abundant supply of eggs 

 for the hatching boxes.* 



At the close of each fish-spawning season it would pro- 

 bably be necessary to set the spawners free, and collect a 

 fresh stock in time for the next season in order to ensure 

 having healthy parents. As lobster hatching and oyster 

 spatting both take place in summer, the pond would then 

 be free from fish, and it would be a simple matter to 

 arrange temporary partitions across the pond, dividing it 

 into two or more compartments, one of which would be 

 used for the berried lobsters and another for oysters and 

 collecting tiles. It is, perhaps, unnecessary to go further 



* The Scottish Fishery Board aim at having 2,500 adult plaice in their 

 .spawning pond this season. 



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