Chase. J 



436 



[October 



105°, and between 270° and 285°, the influence increasing when the 

 moon acts either in conjunction with the sun, or directly upon con- 

 densed air and vice versa. It also shows the existence of disturb- 

 ances, which may be accounted for by some of the causes to which I 

 have already referred. Table III exhibits apparent tendencies to 

 diminution of force near the syzygies, and to increase of force a day 

 or two after the quadratures. 



Table IV is a compendium of the tidal diiferences in the two preced- 

 ing tables. It shows the effect of temperature in producing maxima 

 and minima when the coolest and warmest portions of the earth are 

 submitted to the direct action of the moon (at or near 240° and 45°), 

 low temperature producing a minimum of horizontal force, with a 

 maximum of vertical force, and vice versd. From the variations of 



horizontal force I ~- j and vertical force | ^^ j given in this table, 



Table V is formed, the mean variations of total force ( | being 



' \- f J ^ 



TABLE IV. 



Lunar- Monthly Magnetic Tide. Differences from Monthly Means. 



