92 PRELIMINARY NOTE ON TRAWLING EXPERIMENTS 



It is not, of course, pretended that the same conditions, with the 

 single exception of the difference in time, prevailed for corresponding 

 hauls in two trips. When the physical circumstances are so complex and 

 so variable, no such identity of conditions can be realised ; and, in the 

 absence of a scientific theory of trawling, it is quite impossible to 

 appreciate, except in the roughest manner, in what way an observed 

 difference in the physical conditions may be expected to affect the 

 catch. All I would venture to claim is that, so far as it is possible to 

 do this on a sailing boat, the same ground was towed over on the second 

 trip as on the first, and that, further, when the physical conditions were 

 manifestly unfavourable, and the catch was, in consequence, small, the 

 facts were recognised, and the value of the evidence afforded by the 

 catch in question was duly discounted. Thus, in summing up the 

 statistics so far obtained for Start Bay, I have omitted to include 

 the measurements of the fishes caught in the first two hauls — when, 

 owing to the light winds and calm weather that then prevailed, the 

 catches were relatively small, and the practical experience of the 

 skipper informed me that we had not had "a fair trial." 



Of the three bays selected for investigation, no adequate examina- 

 tion of one — Tor Bay — has, as yet, been made. Two hauls were made 

 in this bay on November 1st. On each occasion the net came up filled 

 with sea-weed — which had drifted into the bay owing to the rough 

 weather that then prevailed outside — and with little else. On the 

 second trip, which was cut short by a change in the weather, no 

 trial could be made in this bay ; nor has any opportunity since been 

 given me of doing what was previously left undone. 



Before proceeding to state the results thus far obtained for Start and 

 Teignmouth Bays, I may make mention of the fact that it was originally 

 my intention to make a certain number of hauls in the deeper water of 

 twenty fathoms and more, outside the limits within which trawling 

 is forbidden. Once more my constant enemy, the weather, has pre- 

 vented more than one such haul being made; but the results of this 

 haul deserve to be recorded. 



The trawl was shot 3 J miles from Berry Head, which bore N.N.W., 

 at 7.30 a.m., on December 3rd, at a depth of 21 fathoms, and was 

 hauled at 11.30 a.m. from a depth of 18 fathoms — after being towed 

 over a distance of about 3 miles in a straight line. The conditions 

 as to wind, &c., under which the haul was taken, appeared to be 

 favourable, and a remark to that effect was made to me by the skipper 

 before the net was hauled. 



The total catch consisted of 157 whiting, whose middle length* was 



* By the "middle," or "mid" length, I mean the length on either side of which half 

 the fish measured were found to lie. 



