338 



NATURE 



[Feb. 13, 1879 



also to tell us about the people and their mode of life, the 

 places of interest in the district, sporting experiences, 

 and the various kinds of culture carried on. Altogether 

 his volume is interesting and a distinct addition to our 

 knowledge of the district over which its author ruled. 



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. No 

 notice is taken oj anonymous communications. 



[ The Editor urgently requests correspondents to keep their letters as 

 short as possible. ITie pressure on his space is so great that it 

 is impossible otherwise to ensure the appearance even of com- 

 munications containing interesting and novel facts.'l 



Weather, Past and to Come 

 Simultaneously with the appearance of some important 

 remarks by Mr. Hyde Clarke, in the article "Sun-Spots and 

 the Nile," Nature, vol. xix. p. 300, I have been called up by 

 a London clergyman of inquiring mind to answer the charge 

 that a paragraph which he cut out of the Times last year, de- 

 claring on my alleged authority that that winter was to be 

 severer in cold than any known for generations had been totally 

 falsified by the event. I would request, therefore, Mr. Editor, 

 a little space in your valuable pages for the following explana- 

 tions : — 



I give priority to Mr. Hyde Clarke, on account of his 

 early labours in demonstrating a periodicity in human affairs, 

 somewhat of the type of the sun-spot period subsequently 

 discovered elsewhere. His remarks, too, now, of the proba- 

 bility of the existence of other periods of about 26 and 

 104 years, and that they " interfere," or mix up, with what he 

 considers a ten-year period, are also worthy of note. In fact, 

 they are the first public consent I have yet seen to my often 

 insisted on conclusion from the Edinburgh earth thermometers, 

 that the explanation of the eleven-year wave of heat exhibited 

 there, being both immediately preceded and immediately fol- 

 lowed by the deepest trough or wave of cold, for each whole 

 eleven-year cycle on either side of it, was precisely caused by 

 the near concurrence just there of two sets of waves of different 

 periods of undulation. But when he goes on to say (line 38, 

 p. 300) that such interference of two or more sets of undulations 

 •'prevented any absolute calciilation as to the future," I object 

 to the ruhng of that sentence. 



The complication may make the matter more difficult. It 

 may oblige the State at last to set apart some good men for pro- 

 fessionally prosecuting that subject, and to put them into a 

 dungeon if they attend to anything else. But that is all ! Two 

 or three, even six or seven planets, pulling away at the earth 

 and the earth at them in periods of different lengths and with 

 different degrees of energy, do not prevent physical astronomers 

 predicting the final outcome of it all on the earth's motion from 

 day to day, and even minute to minute, and the alleged case of 

 impossibility is only one of like kind. 



But to the clergyman with the inquiring mind I would answer 

 as follows : — 



1. What I did write, in the summer of 1877, 0° the future 

 weather is to be found at p. "25" of vol. xiv. of the " Edin- 

 burgh Astronomical Observations," a volume so liberally distri- 

 buted by H.M. Government to scientific societies and libraries 

 in London that no one there need have any difficulty in referring 

 to my exact words if they are thought of consequence by any 

 body. 



2. Those words are, at all events, as to their general scope 

 and bearing, widely different from the newspaper cutting alluded 

 to. For while that treats only of a cold winter, my first and 

 leading contention in the book was not about cold at all, but 

 about heat. Namely, that the Edinburgh earth-temperature 

 measures for forty years past show that a great heat-wAve comes 

 upon the earth from without, presumably from the sun, every 

 eleven years, nearly ; and that the date of the next such heat- 

 wave was ♦' 1879-5, within limits of half a year each way." 

 According to which the coming summer and autumn of this 

 year may prove glowingly hot, and next winter unusually mild, 

 in obedience to a grand cosmical action upon the earth as a 

 whole. And who has yet disproved that ? 



3. My second, but only second and inferior, contention was, 

 that such eleven-year heat-wave, of solar origination— contrary 



to the usual ideas of the learned as to the crest of a wave being 

 removed from its trough or lowest point by about half of its 

 length — was, in this case, both immediately preceded and imme- 

 diately followed by a trough of extreme cold ; the extremest 

 cold, or lowest trough of each whole eleven years period on 

 either side of the heat-wave's crest. Wherefore I contended 

 (in 1877) that we had then still, between us and the good, 

 warm time coming, a trough of extreme cold to wade through ; 

 and I did say that that preliminary cold-wave might be expected 

 about l878'o " within limits of three-quarters of a year." 



4. Because the winter of 1877-78 was not cold, and the 

 winter of 1878-79 is now very cold, in Great Britain, the 

 clergyman holds that my prediction was totally falsified. But 

 to that conclusion I oppose the following consideration : — Is the 

 surface of Great Britain large enough to be taken as expressing 

 the condition of the whole globe under a cosmical influence 

 from space without ? Is not China much larger than the so- 

 called Great Britain, and was not last winter preternaturally cold 

 in China, with snow and ice down to the sea-coast even in 

 lat. 29°, and inland such long-continued frosts and dry weather, 

 that thence no crops, and the dreadful famine with depopulation 

 of whole provinces ? 



Is not also the surface of North America larger than that of 

 Great Britain ; and at a central station of the former, Manitoba 

 (as worthily reported and notified by Prof. E. D. Archibald in 

 Nature, vol. xix. p. 266) was not the December of the present 

 winter astonishingly warm, almost hot, or no less than 25" above 

 the mean temperature of former Decembers there ? 



5. Hence, if we look beyond our own immediate coasts, I 

 suspect that the deficiency of radiation from the sun, called the 

 cold trough, may have occurred, in reality, not far from the 

 date I suggested in 1877, viz., in 1878*0. But as such influence 

 from without has to act on the solid earth practically through the 

 medium of an absorptive, locomotive, double revolving atmo- 

 sphere, its full and extremest effects are experienced in different 

 manners and at different dates in different parts of the earth. 



Wherefore the "meteor" then becomes an affair for terres- 

 trial meteorologists, not for astronomers, to follow up and 

 explain ; though the former may glean some useful hints from 

 what the latter have long since ascertained as to the lunar tide - 

 wave : viz., that it is raised, or coincides most nearly with a 

 meridian full moon, neai- the middle of the Pacific ; but at far 

 different and later dates at other places, according to the length 

 and difficulty of the path by which the tide-wave, once raised, 

 has to travel to reach them, PiAZZi SMYTH 



15, Royal Terrace, Edinburgh, February I 



Sun-Spots and the Plague 



Apropos of the plague — I do not know whether the following 

 curious coincidence has been noticed. In that admirable work, 

 John Graunt's "Natural and Political Observations upon the 

 Bills of Mortality" (second edition, London, 1662), which is 

 probably the earliest treatise on vital statistics, I find the follow- 

 ing statement (p. 31): — "There have been in London, within 

 this age, four times of great mortality, that is to say, the years 

 1592 and 1593, 1603, 1625, and 1636." He shows that large 

 numbers died of the plague in each of these years. Now, if we 

 take the solar period to be loj years, nearly in accordance with 

 Dr. Lamont's and Mr. J. A. Broun's estimates, we get the sub- 

 joined table, which sufficientiy explains itself. 



U 



1592-5 

 1603 



1613-5 

 1624 



1 634*5 

 1645 

 1655-5 

 1666 



11718-5 



Plague in London 



Great Plague in Naples ... 

 ,, of London... 



,, at Marseilles 



1592-3- 

 1603. 



1625. 

 1636. 



1656. 

 1665. 



1720. 



If this particular coincidence has not already been pomted 

 out, it deserves notice as supporting the theory that the rate of 

 mortality is remotely connected with the solar period. There 

 may be several chains of causation leading to the increase of 

 mortaUty, but one chain is doubtless through the Asiatic fammes, ■ 

 which would naturally develop the worst forms of germ disease. 



W. Stanley Jevons 



