1864.] 



435 



[Chase. 



the lunar zenith and nadir effects, and the evidence in the partial 

 '' establishment" of the moon's tides that most of her magnetic influ- 

 ence is exerted indirectly on the asthcr, through the intervention of 

 atmospheric attraction-currents. 



Tables II and III were formed by taking the mean of the hourly 

 averages, on the twenty-four days in each lunar month which are 

 most nearly indicated by the angular positions given in the first 

 column. Each of the tabular numbers for 1844 and 1845 represents 

 the average of two hundred and eighty-eight hourly observations ; 

 each of the numbers for 1846, the average of two hundred and sixty- 

 four observations, with a few exceptions of holidays and other omit- 

 ted days, for which the missing numbers were interpolated. Table 

 II indicates a tendency to mean lunar influence between 90° and 



TABLE III. 



Lnnar-Monthlij Magnetic Tide of Vertical Force. 



* The value of one scale division varies from .00051 to .00091 of the Vertical 

 Force. 



