414 



NA TURE 



[March i, 1906 



drought are recorded, besides the preliminary drought years 

 ot '557-I55 8 - Th e fifth will, then, cover the equally' well 

 marked cycle of drought, which, beginning in or about the 

 year 1S60, has continued with scarcely an exception up to 

 the present." 



This was written in 1902, and it is noticeable that, as 

 required by the cycle, the intervening years have proved of 

 normal rainfall in northern China. Proceeding, I stated : — 

 We have thus four well marked eras of 29925 years, 

 the beginnings of which in each case were marked by 

 perfectly similar climatal phenomena, each being charac- 

 terised as a period of drought in some special locality. It 

 has always seemed to me that meteorologists have been in 

 the habit of excessive generalisation, and that the true way 

 to arrive at the secular variations of climate is to com- 

 pare all observations made within a limited locality, where 

 the conditions are more or less specialised. The mean rain- 

 fall of China, as I remarked at the beginning, would not 

 have afforded the necessary data for such a comparison as 

 I have attempted, the reason being that droughts in north 

 and south China are in effect complementary, and never 

 occur contemporaneously : and herein lies the key to the 

 phenomena. 



" According to the accepted theory of the ' monsoon,' it 

 is produced by the excessive heating of the continent of 

 Asia between the degrees of 35 and 45 N.L. which causes 

 the rarefied air to flow off and leaves a partial vacuum to 

 be filled in by moist warm air rushing across the equator. 

 If from any cause the heat radiated from the sun be greater 

 one year than another, the regions where the monsoons are 

 elaborated are raised to a higher temperature, and the 

 force of the monsoon increased, and the warm air carrying 

 an extra supply of moisture is carried further north and 

 spread over a wider area; hence the north of China, the 

 usual limit of the monsoon, is superabundantly watered. 



" If, however, the heating of the surface be insufficient 

 to set up the normal circulation, the moisture from the 

 tropics is dumped down in or about the latitude of the 

 Yangtse basin, and mid-China receives a superabundant 

 supply of rain, while the entire north is parched, and 

 famine in one or more province is the result. Hence a 

 wet summer in Shanghai is rarely or never accompanied 

 by a sufficient rainfall in the north." 



Similar conditions to a large extent prevail in India, and 

 hence it has happened that the latter third of the last 

 century was a period of drought and famine, which severely 

 taxed the resources of the country. I wound up the note 

 with the following remarks: — " It is not for me to suggest 

 an explanation. But the 299^ year will probably be found 

 to depend on some hitherto unsuspected cosmical cause." 



I do not pretend in this to take any credit to myself for 

 any discovery. My part was confined to drawing up a 

 column of centuries divided into three lines; in one was 

 marked the year, in the second the dates when sun-spots 

 had been observed, and in the third the years when 

 droughts had been recorded in the northern provinces ; in 

 each of the latter a dark line was drawn across the column. 

 The result was remarkable at the first glance, the dark 

 lines congregating themselves thickly at "the ends of the ' 

 seventh, tenth, thirteenth, and sixteenth centuries, the rest 

 being almost a blank. Personal experience showed me how 

 the nineteenth century had followed the same rule. Mr. 

 Clough's observations may therefore be looked upon as fully 

 borne out by Chinese records ; and it only remains to 

 ascertain the cause of the phenomenon, which has certainly 

 had a very considerable effect on the history of Asia. 



I may point out the curious coincidence that the climatic 

 cycle of about thirty-four years seems to agree with three 

 sun-spot cycles, while the greater period of 299J would 

 seem to correspond with twenty-seven. 



Shanghai, January 8. Tnos. W. Kingsmill. 



The Origin of Bronze. 

 In connection with Prof. W. Gowland's remarks on trie 

 origin of bronze in his presidential address to the Anthropo- 

 logical Institute, abstracted in your issue of February 15 

 (P- 3 Sl ). 't may be of interest to direct attention to' the 

 Fad thai Plutarch, in his " De defectu oraculorum," 

 refers to worked-out copper deposits in the island ol 

 Eubcea, from which were formerly manufactured swords 



NO. 1896, VOL. 73] 



which were " cold-forged " (^vxpy^aros), and in this con- 

 nection he quotes jEschylus, who mentions a " self- 

 sharpened (aurdflnKTos) Eubcean sword," self-sharpened 

 meaning, I presume, sharpened without fire. I believe 

 that bronze containing only a small proportion of. tin is 

 malleable in the cold, but do not know if this would be 

 the case with that referred to by Prof. Gowland as con- 

 taining antimony. It would be interesting to know if 

 tin is associated with copper in Eubcea. Swords of pure 

 copper would hardly be of much use. 



John W. Evans. 

 Imperial Institute, February 23. 



Result of War affected by Soldier's Stature. 



Mr. Twigg at p. 340 of your issue of February 8 points 

 out that the Japanese had an unquestionable advantage 

 in the recent war, as being smaller than the Russians — 

 they were smaller targets for fire-arms. This is quite 

 correct, but the advantage is inversely as the cubes of 

 their heights, and not as the squares only, which would 

 only apply to plank dummies. Bullets come from all 

 sides, and not from the front only, so that the thickness 

 of the men's bodies must be taken into account as well as 

 their height and breadth. The average targets offered by 

 each to the enemy are (taking Mr. Twigg's figures) as 

 the cubes of 1585 and 1642, or as 106 to 118, an advantage 

 in favour of the Japanese of about 12 per cent., or nearly 

 double that calculated by Mr. Twigg. 



W. E. Warrand. 



Westhorpe Hall, Notts, February 24. 



TWO BOOKS ON BIRDS. 1 

 ^P O watch the ways and habits of birds is a taste 

 -*■ which is growing rapidly. Some watchers of 

 birds, indeed, are not content to stop at observing 

 their habits ; they want to know how the birds 

 acquired those habits and of what use they are to 

 them. They speculate upon what a certain habit, if 

 persisted in, may ultimately lead to. They wish to 

 know, among other things, how a bird came by its 

 colours, and what purpose in the bird's economy is 

 served by, for instance, the red inside to its mouth, 

 seen only when it gapes. And when careful, minute, 

 and scrupulously accurate observers write down on 

 the spot what they see, or think they see, natural 

 history will always be the richer for their labours ; 

 and the theories and speculations which these in- 

 quisitors weave from what they have seen and heard 

 cannot fail to prove interesting and suggestive 

 reading. 



Mr. Selous, at once the pioneer and the great 

 exponent of this " close observation," who in a former 

 work on bird watching touched upon the birds of the 

 Shetlands, returned to his loved islands two years 

 later, and now gives us a whole volume devoted to 

 their birds and seals. In some three dozen short 

 chapters he discourses, with digressions, delightfully 

 upon his experiences. With the exception of a few 

 " peckings," and minor interpolations — mostly having 

 to do with the working out of ideas jotted down in 

 the rough — the chapters contain his journal, written 

 from day to day amidst the birds with whom he lived 

 without another companion on one or other of these re- 

 mote islands, " hated by thousands " of birds, and feel- 

 ing himself the most unpopular person on the island. 

 Nothing more need be said to recommend the book 

 to the notice of those who follow birds in the field. 

 For his digressions, leading him sometimes wide of 

 the subject of birds, the author does not apologise. 



1 "The Bird Watcher in the Shetlands. With some Notes on Seals— 

 and Digressions." By Edmund Selous. Pp. xii + 338 ; with 10 illustrations 

 by J. Smit. (Lcndon : 1. M. Dent and Co., 1005O Price 10s 6d. net. 



" Nature-Tones and Undertones." Being Sketches of Life in the Open. 

 Illustrated by Photographs from Nature. By J. Maclair Boraston. Pp. 

 223. (London and Manchester : Sherratt and "Hughes, 1905 ) Price 6s. 



