NovKUBfjj 13, 1903.] 



SCIENCE. 



r;i5 



iiiinpjinidn oxposi-ii to the sky, is, for icoearcli 

 |iurj)()ses, work of llie tenth order of importance. 



With reference chiefly to Dr. Jleldrum's 

 paper, I added: 



Surely here is evidence enough, evidence which 

 should no longer allow us to deceive otir.selves as 

 to the present state of meteorology. A most im- 

 portant cycle has been discovered, analogous in 

 most respects to the Saros discovered by the 

 astronomers of old, indeed, in more respects than 

 one, maj' the eleven yearly period be called the 

 Saros of meteorology, and as the astronomers of 

 old were profoundly ignorant of the true cause of 

 the Saros period, so the meteorologists of the 

 present day are profoundly ignorant of the true 

 nature of the connection between the sun and 

 the earth. 



What, therefore, is necessary in order to dis- 

 cover the true nature of this nexus'; Two things 

 are necessary, and they are these. In the first 

 place, we must obtain an accurate knowledge of 

 the currents of the sun, and secondly, we must 

 obtain an accurate knowledge of the currents of 

 the earth. The former of these denuinds the 

 united efforts of photography and spectrum anal- 

 ysis, and the second of these demands the pursuit 

 of meteorology as a physical science, and not as 

 a mere collection of weather statistics. W'lien 

 the.se demands are met — and in spite of the Mrs. 

 Partingtons who are endeavoring to prevent this, 

 they will soon be met — we shall have a science 

 of meteorology placed on a firm basis — the meteor- 

 ology of the future.* 



At this time the Indian authorities were 

 quite alive to the importance of such in- 

 vestigations as these. India is in the 

 tropics, India is a child of the sun, the 

 inhabitants depend almost entirely upon 

 the beneficent rains which seemed, in some 

 way or another, to depend upon solar ac- 

 tion. India also had then the crerms of one 

 of the best equipped meteorological organ- 



' I very much regret that, in the article quoted, 

 my reference to Carlyle's German ' Dry as dust,' 

 as a patient enquirer who would eventually ap- 

 portion credit to all meteorological workers, has 

 been misunderstood by some of my (Jerman 

 friends. Relying on imperfect dictionaries, 

 which have told them that a mere ' bookworm ' 

 was meant, they have missed the high compli- 

 ment I intended to pay them. 



izatious which exist on the surface of the 

 planet, and the meteorologists felt that 

 there was something liehind their meteor- 

 ological registers which might be assisted 

 by taking a very official step and going to 

 headquarters, headquarters being the sun. 

 When I was in India, in 1872. Lord Mayo, 

 the then Viceroy, did me the honor to a-sk 

 me to go to Simla with a view of choosing 

 a site for a proposed Solar Phj'sics Obser- 

 vatory. That is thirty years ago! Un- 

 fortunately, I was secretary of the Duke. 

 of Devonshire's Commission, which was 

 then sitting, and I could not get leave, and, 

 therefore, could not go; the scheme, which 

 was then before the Indian authorities— 

 whi;:h, if I may say so, was altogether 

 grandiose and extravagant— fell through. 



In 1873, the idea of the possible connec- 

 tion of solar and magnetic changes had got 

 so far that the nmgnetic and meteorological 

 department of the Royal Observatory at 

 Greenwich, which had been established in 

 1838, received an important addition. A 

 photo-heliograph was set up in order to 

 continue the daily photographic record of 

 the sun 's surface, begun at Kew in 1865. 



In the same year Kiippen found that the 

 maximum temperature occtu-s in the years 

 of sun spot minima and the reverse, years 

 with many spots are cool years.* 



Of special importance for the ccmnecticm 

 between the temperature on the earth's 

 surface with the siui's spotted area is the 

 fact that the temperature cur^'e (mean 

 number for the whole earth) and the curve 

 representing the sun-spotted area is iden- 

 tical in all the irregularities. 



In the tropics in the 



Year before the sun spot Min.. the temperature 

 is 0.41° higher than the mean. 



Year before the sun spot Max., the temperature 

 is 0.32° lower than the mean. 



The variation is thus 0.73°. 



* \V. Kiippen, ' Vber mehrjiihrige I'crioden der 

 Witternng,' Xcilschiift f. Mclrorologir, Bd. VIII., 

 1H73, pp. 241-248 and 257-268. 



