CHROMOSPHERE AND SOLAR PROMINENCES. 401 



liquid as measured by the quantity named. Now, on the surface of 

 the earth a rain-storm which deposits two inches in an hour is very 

 uncommon — in such a storm the water falls in sheets. It is easy to 

 see then, that the quantity of liquid pouring from the solar clouds is 

 so enormous that the drops could not be expected to remain separate, 

 but must almost certainly unite into more or less continuous masses 

 or sheets, between and through which the gases ascending from be- 

 neath must make their way. And since the weight of the vapors 

 which ascend must continually equal that of the products of conden- 

 sation which are falling, it is further evident that the upward currents, 

 rushing through contracted channels, must move with enormous 

 velocity, and therefore, of course, that the pressure and temperature 

 must rapidly increase from the free surface downward. It would 

 seem that thus we might explain how the upper surface of the hydro- 

 gen atmosphere is tormented by the up-rush from below, and how 

 gaseous masses, thrown up from beneath, should, in the prominences, 

 present the appearances which have been described. Nor would it be 

 strange if veritable explosions should occur in the quasi pipes or chan- 

 nels through which the vapors rise, when, under the varying circum- 

 stances of pressure and temperature, the mingled gases reach their 

 point of combination ; explosions which would fairly account for such 

 phenomena as those represented on page 400, when clouds of hydrogen 

 were thrown to an elevation of more than 200,000 miles with a velocity 

 which must have exceeded at first 200 miles per second, and very 

 probably, taking into account the resistance of the solar atmosphere, 

 may, as Mr. Proctor has shown, have exceeded 500 ; a velocity sufficient 

 to hurl a dense material entirely clear of the power of the sun's attrac- 

 tion, and send it out into space, never to return. 



But our limits forbid indulgence in such speculations ; nor can we 

 stop to discuss the interesting question concerning the relation between 

 these solar eruptions and magnetic storms upon the earth. It must 

 suffice to say that, while it is not probable that our greater magnetic 

 disturbances are caused directly by solar influence, it is very nearly 

 certain that every violent paroxysm upon the sun is distinctly and 

 immediately responded to by our magnetometers. 



Whether these solar storms produce any other effects upon the 

 earth, has not been ascertained. Some are so sanguine as to expect 

 that in the study of these phenomena will be found the key to 

 many puzzling problems of terrestrial meteorology. We cannot say 

 that we share the expectation ; but the subject is certainly worthy of 

 careful examination, and it is not possible to doubt that faithful labor 

 in so new and fertile a field will be rewarded, if not with precisely the 

 result anticipated, yet with some rich harvest. 

 vol. iv. — 26 



