The ephemeral or evanescent character of many of the so-called sun-spots, removes them from the domain of sun-phenomena, otherwise than in appearance.
Figures that are Deceptive.
Some of these spots even of large dimensions come into the field of view almost instantaneously; and as suddenly disappear. Thus Krone "observed a spot of no inconsiderable dimensions which sprang into existence in less than a minute of time." Dr. Wollaston says:—"I once saw with a two-inch reflector a spot which burst in pieces as I was looking at it." Biela also notes that "spots disappear sometimes in a single moment." Sir William Herschel "turned away his eyes from a group of spots he was observing, and when he looked again the group had vanished."
Of those who attempt to make an estimate of these phenomena by mathematical formulæ, we would ask, What velocities must these sudden and apparently widespread outbursts represent, if they take place at the sun?
Effects of these Wonderful Phenomena.
That this phenomenon is a result of an interruption of the solar current is rational to suppose. It is indisputable that the interruptions which produce these manifestations have an important bearing upon terrestrial phenomena. Winds, storms, vegetation, healthfulness, are manifestly influenced, and in a measure controlled by these perturbations.
Mistaken Conceptions.
The claim of many scientists that spot periods may be calculated, and classified, possesses no element even of probability, much less of fact, to sustain the supposition. The evanescent character of many of these spots places them beyond the sphere of statistical calculation.
May not be Tabulated.
Not even concerted and systematic investigation can insure reliable conclusions, for persons separated by even inconsiderable distances would not always observe precisely the same spot manifestations. Moreover, the spots appear and vanish so quickly that no correct estimate can be made at any single locality. As well attempt to map and chart the aurora borealis.