308 Anniversary Meeting. [Nov. 30, 



not very severe magnetic storm, as much work must have been done 

 by the sun in sending magnetic waves out in all directions through 

 space as he actually does in four months of his regular heat and 

 light. This result, it seems to me, is absolutely conclusive against 

 the supposition that terrestrial magnetic storms are due to magnetic 

 action of the sun ; or to any kind of dynamical action taking place 

 within the sun, or in connexion with hurricanes in his atmosphere, 

 or anywhere near the sun outside. 



It seems as if we may also be forced to conclude that the supposed 

 connexion between magnetic storms and sun-spots is unreal, and that 

 the seeming agreement between the periods has been a mere coinci- 

 dence. 



We are certainly far from having any reasonable explanation of any 

 of the magnetic phenomena of the earth ; whether the fact that the 

 earth is a magnet; that its magnetism changes vastly,, as it does from 

 century to century ; that it has somewhat regular and periodic annual, 

 solar diurnal, lunar diurnal, and sidereal diurnal variations ; and (as 

 marvellous as the secular variation) that it is subject to magnetic 

 storms. The more marvellous, and, for the present inexplicable, all 

 these subjects are, the more exciting becomes the pursuit of investi- 

 gations which must, sooner or later, reward those who persevere in 

 the work. We have at present two good and sure connexions be- 

 tween magnetic storms and other phenomena : the aurora above, and 

 the earth currents below, are certainly in full working sympathy with 

 magnetic storms. In this respect the latter part of Mr. Ellis's paper 

 is of special interest, and it is to be hoped that the Greenwich obser- 

 vations of earth currents will be brought thoroughly into relation 

 with the theory of Schuster and Lamb, extended, as indeed Professor 

 Schuster promised to extend it, to include not merely the periodic 

 diurnal variations, but the irregular sudden changes of magnetic 

 force taking place within any short time of a magnetic storm. 



In my Presidential Address of last year I referred to the action of 

 the International Geodetic Union, on the motion of Professor Foerster, 

 of Berlin, to send an astronomical expedition to Honolulu for the 

 purpose of making a twelve months' series of observations on latitude, 

 corresponding to twelve months' simultaneous observations to be 

 made in European observatories ; and I was enabled, through the 

 kindness of Professor Foerster, to announce as a preliminary result, 

 derived from the first three months of the observations, that the 

 latitude had increased during that time by ^ sec. at Berlin, and had 

 decreased at Honolulu by almost exactly the same amount. The 

 proposed year's observations, begun in Honolulu on the 1st of June, 

 1891, were completed by Dr. Marcuse, and aa elaborate reduction of 

 them by the permanent Committee of the International Geodetic 

 Union was published a month ago at Berlin. The results are in 



