526 Influence of the Moon on Rain. [Sept. 



The observations of Schtjbler were made during eight years at Munich, four 

 years at Stuttgard, and sixteen years at Augsburg. As a good meteorological 

 register has been long kept at Geneva, the author thought it would be interesting 

 to ascertain from the tables, (which have been carefully published in the Biblio- 

 theque of that city,) whether, during a period of thirty-four years, viz. from 1800 

 to 1833, any inferences could be drawn for or against the popular opinion on 

 the subject of lunar influence. 



He finds, during these thirty-four years, the number of rainy days and quantity 



of wafer fallen, to be as follows : 



Rainy days. Water fallen. 



At the new moon, 123 432- lines. 



First quarter,.... •• 122 4296 ditto. 



Fullmoon 132 415-9 ditto. 



Last quarter, , 128 368-6 ditto. 



Throughout the whole period, 3,657 968 in. 93 lines. 



Thus it appears, that during thirty-four years, or 12,419 days, comprehending 



420 synodic revolutions of the moon, there have been 3,657 rainy days. This 



gives for every 100 days, 29-45 rainy days ; and we find, that 



For every 100 days of new moon, 29'29 have been rainy. 



Do. do. first quarter, 29-05 do. do. 



Do. do. full moon, 31 -43 do. do. 



Do. do. last quarter, 30*48 do. do. 



Hence, it is evident, that during these thirty-four years at Geneva, the days of 



new moon and the days of the first quarter have been just about as liable to be 



rainy days as any other common day of the month ; while the days of full moon 



and those of the last quarter have been rather more liable. But although the 



days of full moon have been rather more frequently wet days than those of the 



new moon, it does not follow that more water has fallen at full moon, than at the 



change. The result of observation in that respect is as follows : 



For every 100 days of new moon, there fell 102-9 lines. 



Do. do. first quarter, do. 102-3 do. 



Do. do. full moon, do. 90*0 do. 



Do. do. last quarter, do. 89*9 do. 



The average quantity for 100 days is 93*6 lines, whence it appears, that at 



the new moon, the first quarter, and the full moon, more water has fallen than 



on common days ; at the last quarter, less. The quantity fallen on the total of 



the lunar phases, surpasses that on other days in the proportion of 98 to 93*6. 



Another question is, whether a change of weather is more liable to happen on 



the four principal days of the lunar phases than on common days. But it must 



be first decided, what is meant by the term change of weather. 



, This term should, the author thinks, be limited to a change from clear weather 



to rain, or from rain to clear weather, and not be understood to include, as some 



meteorologists make it, all changes, such as that from calm to windy, or from 



clear to cloudy, &c. As the author accepts it, the weather must have been 



steady during two days at least ; that is, that the weather has been clear, or 



that it has rained more or less during two consecutive days. For example, a 



week has passed without rain ; it rains on the eighth day, and on the ninth, the 



weather is again fine. In this case, according to the author's definition, there is 



no change of weather. 



So also, if it has rained during five successive days, the sixth and seventh mus* 



