278 



NATURE 



i')i 1 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for opmiont 

 expressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications.] 



Daylight Saving? 



Mav i iiKiUi: a few observations with it>;.iid to Prof. 

 Milno's article in Nature of April 6 on Daylight Saving? 

 Leaving aside the inquiry as to whether the clerks of 

 ( Oiiin.ill are happier than those of Kent, to which I am 

 mil ;iM' III give an answer (though it is possible that, as 

 these counties differ in other respects than that considered, 

 .1 nuTc yes or no might have little value as evidence), one 

 may direct attention to the next argument as to workers 

 who have to commence their work at 6 in the morning. 

 The graphic account which Prof. Milne gives as to the 

 hardships which these workers would have to suffer under 

 the proposed scheme, would be heart-rending, had he not 

 thoughtfully supplied the remedy in his last paragraph. 

 Whv should they not start work an hour later in summer? 

 later, that is, according to the new setting of the clocks? 

 This is a " simple solution " on Prof. Milne's own 

 showing. 



In my practical engineering days I found that one of my 

 greatest privations was due to the fact that my evenings 

 had to terminate (in order that I might rise early in the 

 mornings) earlier than those of my friends, and evening 

 engagements were generally inconveniently late. Now, 

 under the proposed scheme all evening engagements, except 

 such as arc organised by these workers for their own con- 

 venience, would take place an hour earlier (absolute time), 

 and consequently the effect of the change would be prob- 

 ably, if anything, an advantage to the 6 o'clock workers, 

 provided they accepted the simple solution suggested. In 

 fact, their day is now disjointed from that of the rest of 

 the world, and under the new scheme this defect would be 

 at least partially remedied. 



Prof. Milne's fifth paragraph seems to be inconsistent 

 with his simple solution. I am surprised to hear the " half- 

 asleep " argument seriously brought forward. If one rises 

 and retires an hour earlier, but works, takes meals, &c., 

 at the old times, the argument is valid, but not, I think, 

 when work, &c., fall in automatically with the new times 

 of rising and retiring. On a journey to Vancouver and 

 back I altered my watch more than twenty times, but felt 

 no inconvenience whatever, because all engagements altered 

 in the same way. 



.As to defects, inconvenience to meteorologists, steamship 

 companies, &c., we must, of course, try to weigh these as 

 justly as possible against the advantages of the scheme, 

 but I think that technical and academic points, and even 

 practical questions like the adjustment of steamship and 

 boat-train .times, should not be allowed to weigh very 

 heavily against any large amount of real advantage to the 

 workers of the country which the scheme might be cal- 

 culated to afford. 



With regard to the last paragraph of the paper, one may 

 remark that the solution suggested, that business people 

 should begin work an hour earlier in summer, really leads 

 us on inevitably to the daylight proposal itself. For if 

 business (apart from factories, &c., with which I have 

 already dealt, which form an obvious exception) begins 

 and ends an hour earlier, then the general activities of the 

 country must follow suit. It would be impracticable, for 

 instance, for shops to open at 7 instead of 8 and close at 

 6 instead of 7 (say) at night, while the shopping public 

 still ordered their doings according to the old times ; and 

 if all business and other people adopted the plan suggested, 

 then all other pursuits engaged in by them must follow. 

 Thus all engagements, trains, and what not must be 

 altered. 



Now, manifestly, by far the simplest mode of carrying 

 out this change would be to alter the clocks, and then 

 allow all the activities of life to go on to the same time 

 schedule as before. Not only is this the simplest way. but 

 I think it will be admitted that it is the only way which 

 would have the slightest chance of being actually realised 

 in practice. 



In conclusion, I may say that mv object in writing has 



NO. 2165, VOL. 86] 



not been to support the daylight saving prui>ukal iiu:U, but 

 rulher to direct attention to what •^i-rn'M to me to be 

 vulnerable points in the argumciu ;umcnts) under 



discussion. Southerns. 



In my note on the so-called Daylight Saving proposal, 

 I repeated a suggestion made by many, viz., •''-• - --■"•i" 

 solution to the whole question would be to i 

 one hour earlier during the summer, and d<. 

 confusing ourselves and others without altering the clocks. 

 Why .Mr. Southerns quotes me as saying one hour later I 

 do not know. The main point, however, to w! ' 

 tically no reference is made is that the majority < ; 

 in Great Britain will, if the time-saving scheme t<^ii.-.-. u.iu 

 force, have to rise at 4 a.m. instead of 5 a.m. for six 

 months in the year. This is increasing darkness and not 

 saving daylight. It is all very well to say that the total 

 population in Great Britain will, if they go to bed one hour 

 earlier, save two and a half million pounds on illumination, 

 but it would only be fair if the promoters of this new- 

 fangled idea would tell the inhabitants of Great Britain 

 how many millions they would have to spend on extra 

 illumination required in the morning. You cannot make a 

 piece of cloth longer by cutting off one end and sewing it 

 on the other. 



Mr. Southerns says that he is " surprised " at hearing 

 what he aptly terms the " half-asleep argument." To be 

 surprised at an argument, however, is not the best way to 

 refute it. Thus I may be surprised, even greatly 

 astonished, at much that Mr. Southerns says in his letter, 

 but I do not expect that the most dramatic exhibition of 

 my personal feeling will carry conviction to his or anyone 

 else's mind. I am therefore compelled to relate a few facts 

 which have a direct bearing on this matter. Of these 

 facts Mr. Southerns is evidently without knowledge, and 

 it may be assumed that others who support this remarkable 

 Bill arc in a like state of darkness. 



In the first place, as the result of innumerable experi- 

 ments and observations by many distinguished investi- 

 gators, it has been definitely ascertained that bodily and 

 mental efficiency are not maintained at the same level 

 throughout the day, and that the course of efficiency, if 

 plotted diagrarnmatically, describes a curve with a morning 

 maximum between ten and eleven : an afternoon maximum 

 about five, and in late workers a third elevation, which has 

 been termed " end-glow." With the afternoon and evening 

 measures of efficiency I am not concerned ; what I 

 wish to emphasise here is that there is a gradual increase 

 in bodily and mental efficiency from the hour of waking 

 up to between ten and eleven in the great majority of 

 workers of all kinds ; i.e. that sleep imposes an inertness 

 the influence of which passes away, only slowly on 

 arising. There is, in fact, what Dr. Howard Marsh, in 

 an interesting book on " The Diurnal Course of Efficiency," 

 calls a " warming-up period." 



Now for the important matter of habit. The results of 

 experiments show that the immediate effect of breaking 

 habits is apt to be detrimental to the outout of work, what- 

 ever that habit may be. So (irmly does habit impress 

 itself upon the reaction of man to his environment, that 

 Patrick and Gilbert, for instance, show that in subjects 

 kept awake for seventy-two hours, and subjected to tests 

 every six hours, the worst results were obtained invariably 

 at the periods ordinarily devoted to sleep, thus showing the 

 recurrent nature of an established habit, and how important 

 is the influence of this upon the output of work, hence for 

 some time after the shifting of time, should it be brought 

 about, we should anticipate that the efficiency of workers 

 would be impaired. J. Milne. 



Seiches in Windermere. 



Windermere is peculiar as regards seiches, since it is 

 nearly divided in two by islands and shallow water near 

 the middle. On account of this the two halves of the lake 

 oscillate independently, but an oscillation can be detected 

 which is due to the uninodal seiche of the whole lake. 

 Because of the shallow water near the middle, this has 

 only a small .implitude and a very long period (69-7m.), and 

 is soon damped out. 



A rerordincf apparatus wa« ^r^^t crt up near the upper 



