398 ANNUAL OF SCIENTIFIC DISCOVERY. 



very generally prevailing opinion. The sailors even had a common saying, 

 that the full moon cut up or devoured the clouds ; and Sir John Herschel 

 had somewhere admitted, that the nights about full moon, particularly at 

 certain seasons of the year, were remarkably cloudless. This indirect influ- 

 ence, then, being admitted, it became more important to trace it, as Mr. H. 

 was doing, to an influence upon the temperature. 



Some years ago, Dr. Foster, an eminent meteorologist, of Bruges, an- 

 nounced to the English Astronomical Society that in weather journals kept 

 by his grandfather, his father, and himself, from 1767 downwards, whenever 

 the new moon fell on a Saturday, the following twenty days were wet and 

 windy. The Society published this, the general idea being, that the state- 

 ment had never been made known before. Since then, it has been found 

 that the Saturday moon has this character even in popular rhymes, and that 

 it is widely believed in among seamen, English, French, Spanish, and even 

 Chinese. 



A writer in the London Aihenceum, after adverting to this circumstance, 

 and stating that in the one instance, in which he had made observations, 

 the theory appeared to be confirmed, makes the following suggestive re- 

 marks : 



"Now here is a curious circumstance: the whole world has the notion 

 widely scattered that a Saturday moon brings wet weather, and science has 

 hardly the means of being positive in the negative. And this is only one 

 such case ; curious effects of the moon are in the popular belief by scores, 

 and their is no refutation, except a priori that is, no refutation at all. 



" Every twenty-nine and a half days is divided into two periods, one of 

 which has many times as much moonlight as the other. That the moon- 

 light must have a great deal of heat when it leaves the moon, is highly prob- 

 able; that it has none when it reaches the surface of the earth is certain. 

 What then becomes of all the heat which it seems almost certain the moon- 

 light brings with it? Sir John Herschel thinks that it is absorbed in the 

 upper regions of our atmosphere; and that some probability is given to this 

 supposition by the tendency to disappearance of clouds under the full 

 moon: a fact observed by himself without knowledge of its having been 

 noticed by any one else, and which Humboldt, he afterwards found, speaks 

 of as well known to the pilots and seamen of Spanish America. If this 

 theory be correct, there is a cause of weather cycles which must produce 

 some effect; an enormous quantity of heat poured into the atmosphere dur- 

 ing one half of the lunar month, and a very small quantity during the other 

 half. In truth, it has been ascertained that the quantities of rain which 

 fall in the four quarters of the moon are not quite the same in the long run. 



But the popular mind gets hold of the question in a different way. It 

 seizes upon the geometrical phenomena of the moon, nothingness, halfness, 

 fulness, and makes the moments of these appearances the times at or very 

 near which change of weather is to take place. According to the recognized 

 old notions, it is enough if a change of weather takes place within three 

 days one way or the other of a change, which gives twenty days every 

 month in which a change is set down to the moon. No wonder this theory 

 is often confirmed. The whole question of moonlight, not position of the 

 moon, both as to its effects on the weather and its asserted effects on vege- 

 table and animal life, is in the earliest infancy, so far as systematic observa- 

 tion is concerned. All that is said about it is mere infallibility." 



