The Weather and the Sun

Abstract

PROF. PIAZZI SMYTH in his communication to NATURE, vol. xx. p. 431, evidently infers that changes in the condition of the sun must needs affect every part of the earth in the same way, whereas we have many meteorological analogies, which favour the notion that totally opposite effects may arise in different parts of the earth from the action of the same primary causes. For example, it is generally assumed that the same tropical heat which gives the primary impulse to the desiccating north-east trade wind of sub-tropical latitudes, furnishes the energy which exhibits itself in the almost constant precipitation under the equator. Any variation in the degree of this heat, should consequently affect localities situated in the region of the trades, and the equatorial calm-belt, in a diametrically opposite manner. Moreover, the notion that the British and Indian rain falls vary together now is altogether inconsistent with the well-known want of similarity between them, both as regards seasonal distribution and annual quantity in the past. It is also remarkable that while the present deluge both here and in India is traced to the sun's “recovering his forces and beginning already to shine after his recent languid spotless years with increased radiation on the great oceans of the south,” the rainfall of England between latitudes 50° and 55° N. reached a decided maximum in 1877, the year when the sun was, to adopt the favourite metaphor, affected with the most extreme languor, and has been very high all through the period of unusually marked spot minimum, from which we are but just emerging.