4o6 WRITDfGS OF JOSEPH E:E>'SY. ri871 



EFFECT OF THE MOOX 0>" THE 'iVEATHER,* 

 (Ftcoo. the STTiithsonum Annial Bepozt £>r 1871. pp. 460, 461.) 



Since the form of the orbit of the earth is affected by the 

 attraction of Venus and the other planets, as well as by its 

 satellite the moon, they must in some d^ree also affect the 

 form of the atmospheric covering of the globe, and tend to 

 produce tides which are of greatest magnitude when they are 

 in opposition to or in conjunction with the sun. But whether 

 these disturbances of the atmosphere or those produced by 

 the moon are of such a character as to give rise to the violent 

 atmospheric commotions denominated storms, is a question 

 which has long agitated the scientific world. 



The times and peculiarities of the meteorological occur- 

 rences are more varied and less definitely remembered than 

 almost any other natural phenomena, and hence the large 

 number of different rules for predicting the changes of the 

 weather. The only way of accurately ascertaining the truth 

 of any hypothesis in regard to atmospheric changes, is that 

 of having recourse to trustworthy records of the weather 

 through a long series of years, and it is one of our objects in 

 collecting meteorological statistic-s at the Smithsonian Insti- 

 tution to obtain the means of proving or dis-proving propo- 

 sitions of the character you have advanc-ed. 



The moon, being the body nearest to the earth, produces 

 the highest tide in the waters of the ocean, and must also 

 proiluce the greatest effect on the aerial covering of the earth. 

 It has not been satisfactorily proved however that the occur- 

 rence of the lunar tides is connected with appreciable changes 

 in the barometrical or thermometrical condition of the at- 

 mosphere. The less pressure of the air at a given place on 

 account of the action of the moon, is just balanced by the 

 increased height of the aerial column. 



The principal causes of the violent changes of the iitmos- 



[L^n^r to a correcfvnder:; in reply to inqiiiries *ad ju^j;;?:;. z? .r. v.c 

 ject-] 



subject-] 



