274 PROCEEDINGS OF THE CALIFORNIA 



of the earth. If the last nientioiied phenomenon is possible in one sun, it is 

 possible in every one of the millions of millions of suns around us, and of course 

 in our sun. That such an eruption of burning hydrogen affected the planets re- 

 volving around that sun we cannot for one instant doubt. To our instrumental 

 vision it was an exhibition of force lasting but a few months, and its effects we 

 can never know, but that they were wonderful must be admitted, and the ef- 

 fects may extend through ages. Doubtless, all new stars that have suddenly 

 appeared with great brilliancy, were the exhibitions of similar causes. 



If such forces are possible for short periods, they are possible and more 

 probable for comparatively long periods. In our sun the forces are apparently 

 evolved in short, moderately regular periods, and also in short and violent out- 

 bursts. The former must have an influence upon the general climate of the 

 earth and of the other planets of our system ; in Mercury and Yenus the effects 

 will be greatly in excess of similar effects on the earth. Even in this year of 

 exceptional heat over the earth, we have the spectroscope revealing an unusual 

 development of incandescent magnesium over the surface of the sun, and from 

 this great disturbance of the average climate of the earth we may reasonably 

 expect other and different disturbances. 



If these forces of the sun's surface exhibit themselves in short and long pe- 

 riods, we can comprehend how periods of almost universal flood ; of earthquakes 

 and volcanic action ; of a climate to develop sub-tropical fauna and flora even 

 within the arctic circle ; of a great ice sheet spreading over the continents from 

 each pole towards and even reaching the equator, may be not only probable, 

 but place the last two phenomena in full accord with the dictum that no vio- 

 lent change of the direction of the earth's axis is admissible. 



The spetrosjope is the present means of gathering observations to develop 

 the law underlying these climatic changes ; and as we note the exhil)itions of 

 the forces upon the surfoce of the sun, and observe the effects upon the earth, 

 we can also study the changes upon Mars and the other near planets. 



But we may not hope to determine the law of connection between the phe- 

 nomena exhibited on the surface of the sun and those on the other planets, 

 within a short time. Unless some wonderful event should happen in our sun, 

 similar to the sudden outburst of luminous hydrogen in the star in the North- 

 ern Crown, to deiuonstrate to us in an hour, the eff'ct such great cosmical 

 changes have upon the earth and other planets of our system, or unless other 

 instrumental means far beyond the known capacity of the spectroscope, should 

 be devised to detect connections between unknown and unsuspected changes ou 

 the sun's surface and limited or irregular periods of earth phenomena, such as 

 years of great heat, cyclonic storms, and earthcpiake and volcanic activity, per- 

 haps even jears of pe.«tilence, a long cycle of years may be required to demon- 

 strate whether and what law lies at the base of my suggestion. 



Like the observers who make their measures to determine the gradual eleva- 

 tion or subsidence of continental shores, we way not learn the results, but we 

 can aggregate observations for discussion by the next generation. 



