observations rejected in this summary fashion; and they, therefore, crossed the Atlantic in great force to observe the Mediterranean eclipse of December, 1870.
It was with some little regret, I must confess, that, as the eclipse of 1870 drew near, I found many of the intending observers proposing to direct their chief attention to the question whether the corona is a solar appendage or a mere glare in our own atmosphere. It seemed to me clear that the atmospheric theory was completely disposed of by the evidence, while a host of interesting questions remained to be answered respecting the nature of the amazing solar appendage thus shown to exist. "I think I have not erred," I wrote in October, 1870, "in insisting that we have ample evidence to prove that the corona is a solar appendage; but what sort of appendage it may be, remains yet to be shown. Observations directed to show whether it is or not a solar appendage will, I apprehend, be a total waste of time; and it is for this reason that I have, at the meetings of the Astronomical Society and elsewhere, deprecated all such observations."—(Preface to second edition of "Other Worlds.") Nay, I fear I even offended one or two by the zeal with which I urged the importance of endeavoring to determine, not whether the corona is a solar appendage, but what sort of solar appendage it may be.
However, the observations were made, photographs and sketches were taken, and the general conclusion drawn from the work of 1870 was that which Sir John Herschel, only six weeks before his lamented decease, enunciated in the following terms in a letter addressed to myfelf: "The corona is certainly extra-terrestrial and ultra-lunar."
Even then, however, some doubts still remained in a few minds. The question of the corona was still mooted in essays and lectures—nay, the atmospheric theory was so successfully defended before the British Association last August, as to lead Prof. Tait to remark that, in his opinion, it was in the main true; while the president of the meeting—Prof. Thompson—even expressed the opinion that the special observations made last December proved that the greater part of the corona was a mere phenomenon of our own atmosphere. It must be pointed out, however, in justice to these eminent mathematicians, that only one side of the question had been adequately presented to them.
Thus another year had passed, and the subject of the corona stood almost exactly as in the autumn of 1870. Well-appointed expeditions were again about to set forth to view an important eclipse, and again the question which the observers had before them was the worn-out problem whether the corona is or is not a solar appendage.
But much more faith was placed in photography than had been the case in 1870. Then, men doubted whether photography could give good pictures of the corona. The colored prominences had been photographed repeatedly; but the finest telescopes had failed to bring the
