THE MOON AND THE WEATHER. 



389 



The confidence to which Toaldo's reasoning and calculations are entitled, 

 may be estimated by comparing the quantities of rain which fall in any other 

 intervals, from which it will be seen that it is not subject to greater, variation 

 than that which exists among the above results. 



M. Arago gives some amusing examples of the kind of speculation and rea- 

 soning in which meteorologists sometimes indulge. Some, he says, found the 

 assumed cycle of nine years on the passage of Pliny, where he says that every 

 fourth, and, more especially, every eighth year, the seasons undergo a kind of 

 effervescence by the revolution of the hundredth moon. Admitting Pliny's 

 maxim to be true, and supposing by the word effervescence we are to under- 

 stand a regular recurrence every eight years of the changes of the weather 

 which took place in the preceding eight years, what are we to conclude 1 Is 

 not the question here, whether the vicissitudes of weather recur at intervals 

 of nine years ? and the celebrated Roman naturalist speaks of a period of only 

 eight years. 



From all that has been stated, it follows, then, conclusively, that the popular 

 notions concerning the influence of the lunar phases on the weather have no 

 foundation in the theory, and no correspondence with observed facts. That 

 the moon, by her gravitation, exerts an attraction on our atmosphere cannot be 

 doubted ; but the effects which that attraction would produce upon the weather 

 are not in accordance with observed phenomena ; and, therefore, these effects 

 are either too small in amount to be appreciable in the actual state of meteor- 

 ological instruments, or they are obliterated by other more powerful causes, 

 from which hitherto they have not been eliminated. It appears, however, by 

 some series of observations, not yet confirmed or continued through a sufficient 

 period of time, that a slight correspondence may be discovered between the 

 periods of rain and the phases of the moon, indicating a very feeble influence, 

 depending on the relative position of that luminary to the sun, but having no ( 

 discoverable relation to the lunar attraction. This is not without interest as a ( 

 subject of scientific inquiry, and is entitled to the attention of meteorologists ; 

 but its influence is so feeble that it is altogether destitute of popular interest as 

 a weather prognostic. It may, therefore, be stated that, as far as observation 

 combined with theory has afforded any means of knowledge, there are no 

 grounds for the prognostications of weather erroneously supposed to be derived 

 from the influence of the sun and moon. 



Those who are impressed with the feeling that an opinion so universally en- 

 tertained even in countries remote from each other, as that which presumes an 

 influence of the moon over the changes of the weather, will do well to remem- 

 ber that against that opinion we have not here opposed mere theory. Nay. we 

 have abandoned for the occasion the support that science might afford, and the 

 light it might shed on the negative of this question, and have dealt with it as a 

 mere question of fact. It matters little, so far as this question is concerned, i 



