Page:Popular Science Monthly Volume 11.djvu/72

62



The solar protuberances had not as yet been directly analyzed in 1866; it was not yet known that a continuous stratum of incandescent hydrogen envelops the bright photosphere of the sun, and that the emission of this gas, in the form of irregular jets, undergoes in the sun variations, phases, which are at least so far related to the sun-spots as to be coincident with them. What mighty physical