82 THE POPULAR SCIENCE MONTHLY. 



of Great Britain and Ireland, chiefly through the exertions of one in- 

 dividual, Mr. G. J. Symons. 



To Dove we are indebted for the law of rotation of the wind, to 

 Redfield for the spiral theory of cyclones, to Francis Galton for the 

 theory of anti-cyclones, to Buchan for an investigation into the dispo- 

 sition of atmospheric pressure which precedes peculiar types of weather, 

 to Stevenson for the conception of barometric gradients, to Scott and 

 Meldrum for an acquaintance with the disposition of winds which fre- 

 quently precedes violent outbreaks ; and, to come to the practical ap- 

 plication of laws, we are much indebted to the late Admiral Fitzroy 

 and the system which he greatly helped to establish for our telegraphic 

 warn'ngs of coming storms. 



Again, the meteorology of the ocean has not been forgotten. The 

 well-known name of Maury w ill occur to every one as that of a pioneer 

 in this branch of inquiry. Fitzroy, Leverrier, Meldrum, Toynbee, and 

 others, have likewise done much ; and it is understood that the mete- 

 orological ofiices of this and other maritime countries are now busily 

 engaged upon this important and practical subject. Finally, the 

 movements of the ocean and the temperatures of the oceanic depths 

 have recently been examined with very great success in vessels dis- 

 patched by her Majesty's government ; and Dr. Carpenter has by 

 this means been able to throw great light upon the convection-cur- 

 rents exhibited by that vast body of water which girdles our globe. 



It would be out of place to enter here more minutely into this large 

 subject, and already it maybe asked what connection has all this with 

 that part of the address that went before it. 



There are, however, strong grounds for supposing that the meteor- 

 ology of the sun and that of the earth are intimately connected to- 

 gether. Mr. Broun has shown the existence of a meteorological period 

 connected apparently with the sun's rotation ; five successive years' 

 observations of the barometer at Singapore all giving the period 25.74 

 days. Mr. Baxendell, of Manchester, was, I believe, the first to show 

 that the convection-currents of the earth appear to be connected some- 

 how with the state of the sun's surface as regards spots ; and still 

 more recently, Mr. Meldrum, of the Mauritius Observatory, has shown 

 by a laborious compilation of ships' logs, and by utilizing the meteoro- 

 logical records of the island, that the cyclones in the Indian Ocean 

 are most frequent in years when there are most sun-spots. He likewise 

 affords us grounds for supposing that the rainfall, at least in the trop- 

 ics, is greatest in years of maximum solar disturbance. 



M. Poey has found a similar connection in the case of the West 

 Indian hurricanes ; and, finally, Piazzi Smyth, Stone, Koppen, and still 

 more recently, Blanford, have been able to bring to light a cycle of 

 terrestrial temperature having apparent reference to the condition of 

 the sun. 



Thus, we have strong matter-of-fact grounds for presuming a con- 



