50 Proceedings of the Royal Physical Society. 



partly accounts for our fishermen capturing with their small- 

 meshed nets so many small fish. 



Whether herring are likely to remain sufficiently near our 

 shores to be within easy reach of the fishermen, or whether 

 they are likely to proceed further and further to sea, we need 

 not discuss at length in the meantime, but it may be pointed 

 out that, if the eggs are capable of hatching in deep water 

 (say in from 60 to 100 fathoms), almost any of the many 

 gravel-coated banks of the ISTorth Sea might serve as spawn- 

 ing beds. As is well known, the North Sea is remarkably 

 shallow. If, e.g., we draw a line from Kinnaird's Head to 

 the Naze on the south of Norway, the depth nowhere exceeds 

 70 fathoms, until we are within some thirty miles off the 

 Norwegian coast. Again we find the 50 fathom-line is about 

 100 miles from the coast between St Abb's Head and Mon- 

 trose; while, in order to get 50 fathoms water off Aberdeen, 

 we require to sail eastwards fifty miles. Between Peterhead 

 and Orkney, however, the 50 fathom-line lies from twenty to 

 thirty miles from the coast. As a matter of fact, there is 

 only one small area off the east coast where a depth of 100 

 fathoms is reached. This area, generally known as the 

 " pot," lies from two to five miles off Fraserburgh, and the 

 greatest depth is 107 fathoms. 



Having seen that the North Sea is, generally speaking, 

 very shallow, let us now inquire as to whether herring eggs 

 are capable of undergoing their development in water from 

 50 to 100 fathoms. The most certain way of proving this 

 would, of course, be to dredge over the offshore fishing 

 grounds during the autumn, with the view of obtaining 

 spawn naturally deposited. Hitherto, for want of suitable 

 boats, it has not been possible to make a thorough examina- 

 tion of the distant fishing banks; and the few attempts 

 made, when on board H.M.S. " Jackal," some forty miles 

 north-east of Fraserburgh, to dredge herring spawn, were not 

 successful. 



Instead of continuing the attempt to dredge spawn from 

 deep water under unfavourable conditions, it occurred to me 

 that it was possible to practically settle the question at issue 

 by depositing eggs in deep water, so as to learn whether or 



