1865. J 1X5 [Chase. 



currents which tend to restore the gravitation equilibrium of the air 

 and water. It may be unwise, ignorant as we are of the true nature 

 of causal efSciency, to assert that one form of force is produced by 

 another, but it is one of the most important duties of true philoso- 

 phy, to observe sequences and correlations. It has long been known 

 that magnetic action may be so directed as either to assist or coun- 

 teract the attractions of cohesion, chemical affinity, and gravitation; 

 it has also been known that, under certain circumstances, disturb- 

 ances of chemical or of cohesive attraction are accompanied by mag- 

 netical disturbances,* but I have now shown for the first time, by 

 independent examinations of the total force, declination, and dip, 

 that disturbances of gravitation are similarly attended. 



It would certainly be very satisfactory, if it were possible, to have 

 some means of exhibiting, by simple laboratory experiments, the 

 direct and mutual convertibility of gravitation and magnetism, but I 

 fear the attempt to reproduce, in any appreciable mechanical form, 

 the magnificent and daily repeated operations in the laboratory of 

 nature which I have feebly endeavored to interpret, must always be 

 futile. In order to obtain even the small amount of disturbance 

 (.00134) which I have noted in the half-daily variation of atmos- 

 pheric weight (Trans. A. P. S., XIII, 121), it would be necessary 

 to take observations at two stations, one of which should be 2.655f 



* "A few years ago magnetism was to us an occult power, affecting 

 only a few bodies; now it is found to influence all bodies, and to possess 

 the most intimate relations with electi-icity, heat, chemical action, light, 

 crystallization, and, through it, with the forces concerned in cohesion; 

 and we may, in the present state of things, well feel urged to continue 

 our labors, encouraged by the hope of bringing it into a bond of union 

 with gravity itself." Faraday : Exp. Res. 2614. 



t Pv X ( \/D' — -v/D) = 3963 X (v/1. 00134 —1) = 2.655. At Singa- 

 pore the daily disturbance of total force is only |^ as great as it should 

 be theoretically. I suspect that the discrepancy is owing mainly to the 

 monsoons and other great temperature disturbances of the station, which 

 shift the lines of force by a kind of conduction polarity. (Faraday, Exp. 

 Res. 3279.) In other important respects there is a satisfactory corres- 

 pondence between Singapore and St Helena. E. g. 



(See "Numerical Relations of Gravity and Magnetism," Sections V, 

 IX, and Faraday's Experimental Researches, III, 321 — 2.) 



