350 



GRISCOM ON METEOROLOGICAL OBSERVATIONS. 



situations would, doubtless, make a valuable addition to the present stock 

 of meteorological facts. 



There are but few opinions, in relation to the subject before us, more 

 general, than that which ascribes to the moon a determinate influence 

 over the atmosphere. It is of material consequence, we conceive, that 

 this opinion should be brought to the test of ample experience by 

 regular and widely extended observation. The most careful set of ob- 

 servations, relative to this part of the science of meteorology, which ap- 

 pears on record, is that of M. Toaldo. The inferences which he draws 

 from a cautious comparison of the weather with the corresponding 

 positions of the moon, during the long period of one thousand one hun- 

 dred lunations, are to the following amount: 



There are ten situations of the moon in each lunation important to 

 meteorology, viz. the four quarters, the perigee, the apogee, the two 

 passages of the equator, (ascending and descending equinoxes,) and the 

 two lunistices, as they are termed by La Lande, viz. the north, when 

 the moon approaches the zenith, and the south, when it is most de- 

 pressed. Then, the probability of a change of weather, compared with 

 the probability of no change, is as follows : 



At New moon, 6 to 



Full moon, 5 



First quarter, 2 1-2 



Third quarter, 2 1-2 



Perigee, 7 



Apogee, 4 



Ascending equinox, 3 3-4 



Descending do. 2 3-4 



Southern lunistice, 3 



Northern do. 2 3-4 



