On the Conservation of Solar Energy: A Collection of Papers and Discussions

About The Book : When, a twelvemonth ago, I ventured to communicate to the Royal Society my hypothesis regarding the Conservation of Solar Energy, I thought it advisable to confine myself to a concise statement of my views, in order to fix the attention of my audience upon the principles of action which I wished to submit for their consideration. That audience, comprising astronomers and physicists more familiar with the intricacies of solar physics than I could pretend to be, would, I thought, prefer the simple statement of my views to an elaboration of proofs, some of which they might possibly have deemed superfluous, and others objectionable in leading their attention away from the simple conception to matters of detail. In the short space of time which has elapsed since the reading of my paper, the amount of positive information regarding solar physics has been greatly augmented. The elaborate report to the American Government regarding the eclipse of 1880 had not appeared at the time I prepared my paper, but has since furnished a striking confirmation of the luminous equatorial extension of the sun which I had represented in a hypothetical diagram; other valuable information has been furnished, by observations in Egypt, of the solar eclipse of last year. The spectroscope, in the hands of Captain Abney and of Professor Langley, has furnished important evidence to the effect that solar rays are absorbed before they reach the outer confines of our atmosphere, pointing to the existence between the two atmospheres of a highly-attenuated medium comprising, according to Captain Abney, hydrocarbons of the ethyle group. The light thrown upon the diflferential motion of the photosphere by Mr. Carrington has been supplemented by the elaborate series of observations on the motion of sun-spots by Dr. Spoerer of Potsdam, and by very recent communications to the Paris Academy by M. Faye, who, although not admitting my hypothesis of a polar inflow current, has resorted to a polar outflow current in order to explain the photospheric polar retardation, and the cyclonic action to which the appearance and motion of sun-spots are attributable.