The Late Total Eclipse

Abstract

ALLOW me to call the attention of such of your readers as are not already aware of the fact that the phenomena I mentioned in my notes of the late eclipse—the “pulsation” of the sun's light just before totality and the simultaneous “wave-shadows”—are recorded by Grant (“Hist. of Phys. Astronomy,” p. 404) as having been witnessed in France during the total eclipse of 1842. He mentions several probable causes or contributing causes among them the unsteadiness of the air, which certainly existed here. I have not been able to find these phenomena (or phenomenon with a double aspect) mentioned in any other work accessible to me, and should be obliged to you for a statement of the explanation now received. To an outsider the (apparent) rarity and local character of the phenomenon seem to cause this difficulty:—If it is owing to any cosmical cause, or one common to any large part of our atmosphere, it would seem that the phenomenon should be more widely seen; if, on the other hand, it is owing to the unsteadiness of the observer's atmosphere, should it not occur oftener?