Nov. 9, 1876] 



NATURE 



reckoned from the ship's chronometers ; that the Sumner line 

 will have been drav\'n east or west of its true position according 

 as the chronometer is slow or fast. He then adds : — 



"And the question now presents itself, which uncertainty is the 

 greater — the uncertainty of latitude, which it is the real object 

 of this problem to remedy ? or the uncertainty of the chrono- 

 metric longitude, which must be used in attempting to find the 

 remedy ? I do not doubt the reply of every practical navigator, 

 that the chronometric longitude is far more uncertain than the 

 latitude ; and if it be so, the whole method falls to the ground." 



Now this passage can only mean that Sumner's Method, while 

 correcting one uncertainty which exists in the ordinary plan of 

 working out rights, introduces another and a greater uncertainty, 

 and so does more harm than good. Unless it means this, the 

 question which uncertainty is the greater is completely beside 

 the point. The statement, however, is wrong in both particu- 

 lai's. Sumner's Method does not remove uncertainty as to lati- 

 tude, it only limits and defines that uncertainty to the extent 

 which the data allow, and it introduces no new uncertainty 

 whatever. Every other method ot working out an observation 

 of altitude and chronometer time gives results which are uncer- 

 tain as to longitude for just the same reason and to just the 

 same extent as are those given by Sumner. 



The ordinary usage, for which Sir W. Thomson desires to sub- 

 stitute Sumner's Method, and with which he contrasts it in 

 showing the superiority of the latter, is to estimate, by dead- 

 reckoning or otherwise, the latitude, and then to compound this 

 information with that derivable from the observation so as to 

 obtain a knowledge of the longitude, and thus be able to say 

 that the ship is at such and such a point. Now this operation is 

 mathematically equivalent to drawing separately the Sumner line 

 for the observation, and an east and west line through the esti- 

 mated latitude, and then taking as the position of the ship the 

 point in which these two lines meet. The result obtained is 

 precisely the same in both cases, but the second plan has the 

 great advantage that each piece of information is exhibited on 

 the chart independently of the other, so that either may be made 

 use of before the other is acquired. As Prof Stokes says, " it is 

 hard to suppose that the mere substitution of a graphical for a 

 purely numerical process could lead a navigator to forget that he 

 is dependent upon his chronometer." 



That Sumner's Method supplies a means of exhibiting 

 for each observation ^'•precisely what that observation gives, 

 neither more nor less " (to use Prof. Stokes' words), is its chief 

 though not its only claim to adoption. The ordinary practice of 

 navigators produces, indeed, results which have a greater show 

 of precision, but the show is fallacious, for the data are not there 

 to warrant it ; in Prof. Huxley's forcible phrase, it is a grinding 

 of wheat-flour from peascods. The question in a word is this : 

 Shall we prefer the ordinary usage, which quietly ignores two 

 causes of uncertainty, to a method which, while it necessarily 

 leaves one of these still untouched, keeps the other constantly in 

 view, and limits it as far as the case admits? J. A. Ewing 



Sea Fisheries and the British Association 



Prof. Newton has kindly sent me a copy of his address to 

 the Biological Section of the British Association at their recent 

 meeting at Glasgow. It contains much interesting matter, and 

 like the addresses delivered by others to the same body informer 

 years, was no doubt listened to with the respect aue to the 

 scientific attainments of the author. 



It is with very great regret, therefore, that I feel it necessary 

 to dispute the accuracy of some of Prof. Newton's ideas, and to 

 point out that my friend made a very important mistake when, 

 towards the close of his address, he spoke of "the falling off in 

 our sea fisheries," and of the Royal Commission of 1863, to which 

 I was secretary, having been appointed "to seek a remedy for 

 it." It wa^ not ascertained then that there was any falling off 

 in our sea fisheries, nor is such known to be the case at the 

 present time. I say this advisedly, because Prof. Newton was 

 evidently not speaking of unsuccessful fishing in any one year 

 owing to that frequent cause of failure — bad weather — but of a 

 general decrease in the supply of sea fish. The Royal Sea 

 Fisheries Commission to wliich he refers, was appointed in 

 1863, in consequence of the clamour of the line fishermen of 

 Sunderland and of the adjacent coasts against the North Sea 

 trawlers, who, it was alleged, were doing their best to ruin the 

 fisheries by the wholesale destruction of spawn and young fish : 

 but who, it appeared, after full inquiry had been made by the 

 Commission, had committed the great crime' of landino; large 



quantities of fish in the local markets, and of underselling the 

 local fishermen. The object of the gentleman who represented 

 the coaiplaints of the Sunderland fishermen toParliament was spe- 

 cially to inquire into the effects of beam-trawling, and the Commis- 

 sion when at work was popularly known as the " 'I'rawling Com- 

 mission ; " but the Government, finding a great deal of interest 

 taken in the fisheries generally, thought it desirable to extend 

 the inquiry into the state of all the sea fisheries around the 

 United Kingdom, and it consequently became the most com- 

 prehensive investigation of the subject that had ever been made. 



The following were the points the Commissioners were in 

 structed to inquire into, as stated in the Commission : — 



" I. Whether the supply of fish from the sea fisheries is in- 

 creasing, stationary, or diminishing. 



" 2. Whether any of the methods of catching fish in use involves 

 a wasteful destruction of fish or spawn, and, if so, whether it is 

 probable that any legislative restriction upon such method ol 

 fishing would result in an increase in the supply of fish. 



"3. Whether any existing legislative restrictions operate in- 

 juriously upon any of such fisheries." 



The conclusion arrived at on the first point by the Commis- 

 sioners — and I would call Prof. Newton's special attention to it 

 — is thus stated in their report : — 



" The total supply of fish obtained upon the coasts of the 

 United Kingdom has not diminished of late years, but has in- 

 creased ; and it admits of further augmentation to an extent the 

 limits of which are not indicated by any evidence we have been 

 able to obtain." 



It is desirable to call attention to the important fact that the 

 abcve conclusion arrived at by the Commissioners was not based 

 on newspaper reports — the coamon foundation of the frequent 

 alarms about the sea fisheries — but on careful and laborious exa- 

 mination of the fishermen in their own towns and villages, ol 

 fishmongers, fishing boat builders, market and railway returns, 

 and every kind of evidence that could be obtained which bore or 

 the question of the supply of sea fish, and the condition of those 

 persons who were dependent on it for their livelihood. 



On the second point of the inquiry the conclusion was thai 

 any legislative restrictions on the methods of fishing would result 

 in a decrease in the supply of fish. 



And on the third point, the Commissioners stated that they 

 found the existing regulations complicated, confused, and un- 

 satisfactory ; many regulations, even of late date, were nevei 

 enforced ; many would be extremely injurious to the interests oi 

 the fishermen and of the community if they were enforced ; and 

 with respect to these and others, the highest legal authorities 

 were unable to decide where, and in what precise sense, thej 

 were operative. 



As Prof Newton started under the false impression that the 

 Commissioners were appointed in order to seek some remedy foi 

 a falling off in our sea fisheries, it is not, perhaps, surprising thai 

 he did not clearly apprehend the meaning of their conclusions, 

 although I should have thought that anyone reading them with 

 ordinary care could havdiy fail to do so. He says : " That 

 Commission reported in effect that there was nothing to be done 

 with our sea fisheries but to leave them alone." There is a 

 despairing tone about this which would be very depressing if ar 

 examination of the Report did not result in showing that the 

 Commissioners deprecated any interference with our sea fisheries 

 for the simple reason that their produce was not falling off, bul 

 was increasing. They recommended, however, the removal ol 

 all vexatious and useless restrictions, and they advised a strict 

 enforcement of such regulations as would prevent the interference 

 in particular cases of one kind of fishing with another kind, and 

 as would conduce generally to the maintenance of order on the 

 fishing grounds. 



Such are the facts of the case ; and I cannot help thinking 

 that if Prof. Newton had given a little more attention to the 

 subject before he delivered his address to the British Association, 

 he would scarcely have expressed himself in the terms in which 

 he did on that occasion. Such statem<ints and opinions from s 

 person in his position, and addressed to a body like the British 

 Association, can hardly fail to have considerable weight with 

 those who heard or read about them ; but more practical mis- 

 chief is likely to result when they are repeated to the fishermer 

 themselves, by keeping them in a continual state of apprehen- 

 sion lest the Government should interfere with their work. Such 

 was the very general fear around the coast when the last Commis- 

 sion began its work, and one of my most difficult and constant 

 duties in connection with the Commission was to satisfy the fisher 

 men that the desire of the Government was to promote the succes 



