26o 



NATURE 



[May 25, 19 1 6 



the manufacture of chemicals by the contact pro- 

 cess in dentistry and in jewellery." 



Mr. Read was ordered abroad for active service 

 while the volume was being- set up. Had he seen 

 all proofs, no doubt imperfections, of which the 

 foregoing- are random examples, would have been 

 eliminated. 



The book is a useful epitome of mineralogical 

 principles and methods, and a convenient small 

 work of reference to the more important rock- 

 forming and economic minerals. C. G. C. 



British Sea Fish: An Illustrated Handbook of the 

 Edible Sea Fishes of the British Isles. By 

 Harold Swithinbank and G. E. Bullen. Pp. xi 

 + 35. (London: Simpkin, Marshall, Hamil- 

 ton, Kent and Co., Ltd.) Price 2s. net. 

 This is a pamphlet of which six pages are devoted 

 to an account of the British sea fisheries, and 

 thirty-five pages to descriptions of some thirty- 

 four species of marketable fishes. The illustra- 

 tions are very small half-tone reproductions of 

 mediocre photographs. The descriptions consist 

 each of about six to ten lines of print summarising 

 the characters of the species ; two or three lines 

 of print giving the range of occurrence ; and of 

 " remarks " dealing mainly with the quality, 

 flavour, and methods of cooking of the fishes con- 

 sidered. We learn from the preface that the 

 work "is to be regarded as in no way scientific," 

 and that it is intended to popularise the cheaper 

 and coarser kinds of sea-fish which at present 

 suffer from prejudice. Considering these limita- 

 tions and the relatively high price of the pamphlet, 

 we find it difficult to think of the particular public 

 to which it is intended to appeal at the present 

 time ; for it is far too small to be of much use to 

 anyone really interested in marine biolog^y, and 

 too expensive to be used in a propaganda. 



J-J- 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for 

 opinions 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.] 



"Summer Time" and Meteorology. 



Recently I have had occasionally to rise at 3 a.m. 

 and to be out between 3 a.m. and 5 a.m. I found the 

 weather misty and relatively verj' cold, with tempera- 

 ture about 45° F. Later in the day temperature rose 

 to 75° F. Clothing suitable for the early morning 

 was quite unsuitable for the day, and (what I specially 

 noticed) vice versa ; it occurred to me that civilised 

 people had unconsciously adopted a day which centred 

 a little later than the time of maximum temperature, 

 thereby securing the nearest possible approach to a 

 uniform temperature in the daily period of their " away 

 from home" existence. In this wav they save them- 

 selves unnecessary trouble in putting on and taking 

 off clothing; and, further, they save themselves un- 

 necessary risk of chills and colds. The change from 

 a temperature of 45° F. to one of 75° F. is equivalent 

 to changing from a cool day of January to a warm 

 day of July. The change ma)- stimulate an4 energise 



NO. 2430, VOL. 97] 



the labourer in the fields; I doubt if its effect on the 

 worker in a city office is good or pleasant. 



The average increase ot temperature from 8 a.m. to 

 9 a.m. in the summer months is nearly 40 per cent, 

 of the increase from 9 a.m. to the maximum about 

 2 p.m. ; and the decrease in humidity (or dampness of 

 the air) from 8 a.m. to 9 a.m. is nearly 50 per cent, of 

 the decrease from 9 a.m. to the minimum humidity in 

 the afternoon (and the rate of change from 7 a.m. to 

 8 a.m. is equally fast). 



Moving the hands of the clock will neither warm nor 

 dry the air. People are therefore being plunged into 

 cooler, damper air through their ignorance (i) of the 

 fact that custom is usually based on the teachings of 

 experience ; (2) of the facts of observation which indi- 

 cate directly what has been the indirect teaching of 

 experience in this case. 



The argument that it is as cold in April at 9 a.m. 

 as it is in May at 8 a.m. is ineffective, because people 

 in England adapt the amount and character of their 

 clothing to the season of the year, and what they feel 

 most is not absolute cold, but relative cold; and rela- 

 tively to the middle of the day it is twice as cold at 

 8 a.m. in May as at 9 a.m. in January. 



There is an element of romance about early rising" 

 if the exf>eriment is not too often repeated. Perhaps 

 one summer will suffice. E. Gold. 



In accordance with the provisions of the Summer 

 Time Act, Greenwich Mean Time will continue to be 

 used for all meteorological observations and publica- 

 tions, so that no discontinuity will be caused during 

 the period when Summer Time is in force. But be- 

 sides the observations which are made by regular 

 observers, many meteorological phenomena of various 

 kinds are from time to time recorded or reported, and 

 it is highly desirable that there should be no ambiguity 

 in these reports, which are often of much interest and 

 importance. The council of the Royal Meteorological 

 Society desires to direct attention to the necessity of 

 stating precisely the time of occurrence in all such 

 cases, and whether the times quoted refer to Green- 

 wich Mean Time or to Summer Time, since the omis- 

 sion of this information may render the record of the 

 phenomenon useless for meteorological purposes. 



Such occasional observations form a valuable addi- 

 tion to those which are made at the permanent ob- 

 serving stations and supplement them usefully ; it is 

 therefore essential that they should be recorded with 

 precision. H. G. Lyons. 



President. 



Royal Meteorological Society, May 19. 



Geologists and Special Constables. 



A recent experience of Canon E. Hill and myself 

 may be useful to geologists. On May 3 we went by 

 train from Lincoln to East Barkwith' Station, on the 

 line to Louth, and walked by a rather roundabout 

 route to South Willingham Station, looking at the 

 structure of the country and for sections of drift. 

 While waiting for our train outside the latter station, 

 a man, in dress and aspect rather above a farm 

 labourer, accompanied by another with a badge of some 

 sort on his coat, came up to us, and in none too civil 

 a tone began to catechise us as to what we were 

 doing, where we were and had been staying, our 

 homes, professions, ages, heights, and the like, about 

 which we gave him full information. Apparently he 

 did not know that there was such a science as geolog\', 

 but after he had received a large amount of biograph- 

 ical information he acknowledged it by saying, in the 

 tone of one rebuking two peccant villagers, that as 



