That the earth’s magnetism is affected by the sun’s condition with respect to spots, seems to have been more clearly made out, though it must be noted that the Astronomer Royal considers the Greenwich magnetic observations inconsistent with this theory. It seems to have been rendered at least extremely probable that the daily oscillation of the magnetic needle is greater when spots are numerous than when there are few spots or none. Magnetic storms are also more numerous at the time of maximum spot-frequency, and auroras are then more common. (The reader will not fall into the mistake of supposing that magnetic storms have the remotest resemblance to hurricanes, or rainstorms, or hailstorms, or even to thunderstorms, though the thunderstorm is an electrical phenomenon. What is meant by a magnetic storm is simply such a condition of the earth’s frame that the magnetic currents traversing it are unusually strong.) Thus far, however, we have merely considered relations which we might fairly expect to find affected by the sun’s condition as to spots. A slight change in his total brightness and in the total amount of heat emitted by him may naturally be looked for under circumstances which visibly affect the emission of light, and presumably affect the emission of heat also, from portions of his surface. Nor can we wonder if terrestrial magnetism, which is directly dependent on the sun’s emission of heat, should be affected by the existence of spots upon his surface. It is otherwise with the effects which have recently been associated with the sun’s condition. It may or may not prove actually to be the case that wind and rain vary in quantity as the sun-spots vary in number (at least when we take in both cases the average for a year, or for two or three years), but it cannot be said that any such relation was antecedently to be expected. When we consider what the sun actually does for our earth, it seems unlikely that special effects such as these should depend on relatively minute peculiarities of the sun’s surface. There is our earth, with her oceans and continents, turning around swiftly on her axis, and exposed to his rays as a whole. Or, inverting the way of viewing matters, there is the sun riding high in the heavens of any region of the earth, pouring down his rays upon that region. We can understand how in the one case that rotating orb of the earth may receive rather more or rather less heat from the sun when he is spotted than when he is not, or how in the other way of viewing matters, that orb of the sun may give to any region rather more or rather less heat according as his surface is more or less spotted. But that in special regions of that rotating earth storms should be more or less frequent or rainfall heavier or lighter, as the sun’s condition changes through the exceedingly small range of variation due to the formation of spots, seems antecedently altogether unlikely; and