Market Whimsies 



All such habits were well known long before any of them had 

 been observed in a tank. And so were the vagaries, the strange 

 departures from their biological routines, that often upset human 

 calculations. Every ground seemed to breed its particular aber- 

 rations from the conventional pattern. Before he shot a trawl, a 

 skipper was as well versed in the irregularities of the living rhythm 

 as in the unevenness of the dead sea-bed. Nothing was too modest 

 or too extraordinary to be neglected as a clue to the potentialities 

 of the water over which a ship was travelling. A bird wheeled. 

 It was joined by another, both with yellow heads, both otherwise 

 marvellously white, except for a sprig of black feathers at either 

 slender wingtip. Before long the sea was alive vvith splashing gan- 

 nets. Herring. And, at that time of year, there might, though it 

 was unlikely, there might just be spawning. If they had spawned 

 then there might be haddock. It was worth a try. But, by now, 

 another trawler was aware of the birds. It was coming towards 

 them out of the horizon. If only that first wheeling gannet had 

 been heeded, the nets would have been shot by this time. Soon 

 the area would be a hot-bed of trawlers. The good skipper was 

 the one who took advantage of every privilege that chance granted 

 him. It might even be a negative privilege, a warning not to shoot. 

 Maybe the echo-sounder would give back a slender trace that did 

 not come from the bottom, a long feathery trace, like a ladder in 

 a silk stocking. That meant dogfish, and where there were dogfish 

 there was probably little else. 



The echo-sounder was, indeed, the greatest gift that technology 

 had given to fishermen. But it would have been presumptuous for 

 the technologist to imagine that he was responsible for its use. 

 He had invented it as an instrument of navigation, a way of indic- 

 ating the depth of water that lay under the keel of a ship. It was 

 the fisherman who recognised its possibilities as a tool in the search 

 for fish. The machine just sent down a team of sounds that fol- 

 lowed one another at regular intervals to the bottom from which 

 they were echoed back to the ship. The length of time it took to 

 make the return journey was a measure of the depth of the water, 



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