j 22 Toaldo's Syjlcm 



The fituations of the rhoon which have a relation to the 

 fynodical revolution, are well known. It may, however, be 

 remarked, that new and full moon are called the fyzigies, and 

 the firft and laft quarter the quadratures. i he perigeum 

 and apogeum are comprehended under the term apfides. 



On account of the difference in the periods of thefe three 

 revolutions, the fituations of the moon do not return in the 

 fame order, till after a long feries of years; and in the differ- 

 ence of their coincidence, connected with the regular efteel: 

 of the fun at each feafon, lies the caufe of the different varia- 

 tions of the weather. The following are the rules which 

 M. Toaldo has deduced from his observations. 



The probabilities that the weather will change at a certain 

 period of the moon are in the following proportions : 



That is to fay, a perfon may bet fix to one, that the new 

 moon will bring with it a change of weather. Each fituation 

 of the moon alters that ftate of the atmofphere which hc-s 

 been oecafioned by the preceding one ; and it feldom hap- 

 pens that any change in the weather takes place without a 

 change in the lunar fituations. Thefe fituations are com- 

 bined, on account of the inequality of their revolutions, and 

 the greateft effect is produced by the union of the fyzigies 

 with the apfides. The proportions of their power to pro- 

 duce variations are as follows ; 



New 



