54 Mr. Chase on Numerical Relations of 



Hours from mean .... 1 h. 2 h. 3 h. 



Means of theoretical ratios . . '500 *866 1 

 Means of observed ratios . . *563 '865 1 



II. Marked indications of an accelerating force are discover- 

 able in the magnetic fluctuations, especially during the hours 

 when the sun is above the horizon. 



Hours from mean 1 h. 2h. 3h„ 



Mean ratios of hourly tidal differences . 100 73 27 



Mean ratios of squares of hourly 1 inn „ A 9 ~ 

 magnetic differences . . J 



See also Thesis V. 



III. There are lunar-monthly barometric and magnetic tides, 

 which may be explained by differences of weight or momentum*, 

 occasioned by the combined influences of solar and lunar attrac- 

 tion, and terrestrial rotation. 



IV. The solar-diurnal variations of magnetism between noon 

 and midnight are nearly identical in amount with the variations 

 of weight produced by solar attraction at the same hours. 



The ratio of the solar to the terrestrial attraction for any par- 

 ticle at the earth's surface being directly as the mass, and in- 

 verselyasthe square of the distance (Mh-R 2 = 35 4,936 h-23,000 2 ), 

 is '00067. The weight of any particle is therefore increased by 

 this proportionate amount at midnight, and diminished in the 

 same proportion at noon, making a total half-daily variation of 

 •00134 in the atmospheric weight, and consequently, according 

 to my theory, in the terrestrial magnetism. 



Theoretical variation '00134. Observed variation '00138. 



V. The magnetic variations at intermediate hours, between 

 noon and midnight, indicate the influences of an accelerating 

 force, like that of gravity, modified by fluctuations of tempera- 

 ture, and by atmospheric or sethereal currents. 



Every particle of air may be regarded as a planet revolving 

 about the sun, in an orbit that is disturbed by terrestrial attrac- 

 tion and other causes. In consequence of these disturbances, 

 there is an alternate half-daily fall toward the sun, and rise from 

 the sun. By the laws of uniformly accelerated and retarded 

 motions, the mean fall and the consequent mean magnetic dis- 

 turbances should occur at 12 h -r \Z2 = 8 h 29' from midnight. 



Theoretical mean 8 h 29'. Observed mean 8 h 31'. 



VI. Some of the magnetic influences appear to be transmitted 

 instantaneously, through the rapid pulsations of the kinetic 



* I believe there ean be no weight without some degree of momentum. 

 See Proc. Amer. Phil. Soc. vol. ix. p. 357. 



