VOL. LXV.] PHILOSOPHICAL TRANSACTIONS. 621 



This table exhibits a comparison of the actual changes of the weather from 

 fair to foul, with the aspects of the moon ; and needs no other explanation than 

 an interpretation of the characters in the last column. 



— frost 1 Any one of these marks placed over a number signifies, that 

 •}• thaw the weather indicated by that mark, continued from the day of the 



fair I month denoted by the number underneath to the day denoted by 



^ rainy i the next following number, bearing some other mark over it. 

 Xir stormy I Thus, in the month of July, rainy weather set in on the 5th, and 

 >|i: snow J lasted till the 15th; from the 15th to the 20th it was fine; when 

 it changed again, and continued rainy till the 22d; then it was fine to the 27th, 

 and rainy again till the 3 1st. 



Such tables of comparison, made yearly for a succession of years, would in 

 the end decide with certainty for or against the popular persuasion of the moon's 

 influence on the changes of our weather; which has some how or other gained 

 credit even among the learned, without that strict empiric examination, which a 

 notion in itself so improbable, so destitute of all foundation in physical theory, 

 so little supported by any plausible analogy, ought to undergo. The vulgar doc- 

 trine about this influence is, that it is exerted at the syzygies and quadratures, 

 and for 3 days before and after each of those epochs. I'here are 24 days there- 

 fore in each synodic month, over which the moon at this rate is supposed to 

 preside; and as the whole consists but of 29 days 12f hours, only 34. days are 

 exempt from her pretended dominion. Hence, though the changes of the wea- 

 ther should happen to have no connection whatever with the moon's aspects, 

 though the fact should be, that they take place at all times of the moon indif- 

 ferently, and are distributed in an equal proportion through the whole synodic 

 month, yet any one who shall predict, that a change shall happen on some one 

 of the 24 days assigned, rather than on any one of the remaining 5-|-, will 

 always have the chances 24 to 5-^ in his favour. Merely because more changes 

 will fall within the greater time, and, on an average, as many more in proportion 

 as the time is greater. It is evident therefore, that this is a matter in which 

 men may easily deceive themselves, especially in so unsettled a climate as that of 

 this island; and the advocates for lunar influence are not to imagine they have 

 fact on their side, unless it should appear, from such tables as these carefully kept 

 for a long course of years, that the changes happening on the days, which they 

 hold to be subject to the moon, are more than those which happen on the ex- 

 empted days, in a much greater proportion than that of 24 to 54. 



The antiquity of the opinion may perhaps be alleged in its favour ; and it 

 may seem an answer to the objection taken from the instability of the weather of 

 this part of the world, that it had its origin in more settled climates. We find 

 it, it must be confessed, in the earliest Greek writers, who probably had it with 



