Page:Popular Science Monthly Volume 4.djvu/417

 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 beneath must make their way. And since the weight of the vapors which ascend must continually equal that of the products of condensation 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 hydrogen 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 channels through which the vapors rise, when, under the varying circumstances 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 attraction, 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.