244 Mr. Crum on the Influence of the Moon. 



may be reminded that it is through a Society like ours that error on such 

 subjects may be expected to be removed from the public mind. There 

 are, certainly, more dangerous errors, but it cannot be doubted that 

 the habit of holding loose notions upon matters even of little import- 

 ance, incapacitates for accurate thinking on those which arc of greater 

 consequence. 



It may be desirable, in the first place, to take a glance at the early 

 history of this belief. I have, therefore, selected a few of the more 

 important of the facts brought together by the learning and industry 

 of Bishop Horsley, and read by him to the Royal Society in 1774. 



Aratus, an astronomer and physician, who lived in the time of 

 Euclid, appears to have been the first to collect, in his book of prog- 

 nostics, the notions of this kind that were prevalent in his day. That 

 work, owing more, it is said, to the quality of the verse in which it is 

 written, than to the interest taken in its statements, procured com- 

 mentators in abundance among the Greeks and Romans. Pliny 

 relates at great length the celestial signs ; Germanicus translated 

 them, and Virgil recommends them to the serious consideration of 

 agriculturists. Aratus prognosticates the weather from a great 

 variety of objects — from the heavenly bodies — from animals, planets, 

 and terrestrial objects, but, from the moon's aspect in particular, he 

 could predict the weather only from one quarter to another. These 

 predictions were founded upon the indications which the moon gives 

 of the existing state of the earth's atmosphere. Thus, he says, if the 

 moon, on the 4th day, cast a shadow, the weather will be fine during 

 the remainder of the first quarter — meaning, that the moon at that 

 early stage, is a delicate test of the clearness of the atmosphere. 

 Again, the bluntness of the liorns in the new moon is a sign of 

 approaching rain, for if the air were clear, they would be of their 

 natural pointed shape. And after the half moon, the horns being 

 then always blunted, other indications are given for predicting the 

 weather till the full moon. 



But the vulgar, says Dr. Horsley, soon began to consider those 

 things as causes, which had been proposed to them only as signs. The 

 manifest eff'ect of the moon on the ocean, while the mechanical cause 

 of it was unknown, was interpreted as an argument for her influence 

 over all terrestrial things ; and these notions were so consistent with 

 the visionary philosophy of the times, that such men as Theophrastus 

 and Varro, who should have been its opponents, ranged themselves on 

 the side of the popular prejudice. Theophrastus says that the new 

 moon is generally a time of bad weather ; the light of the moon being 

 wanting, and that changes of the weather generally fall on the new and 

 full moon, and on the quadratures. Pliny had his eight critical days 

 for changes of the weather, which were the days of new and full moon, 

 the quadratures, and the four octagonals, or rather the nearest odd 

 numbers to these days, viz. the 3d, 7th, 1 1th, and so on ; for besides 



