1864.] 369 [Chase. 



general correspondence between Cballis's laws of molecular action 

 and the laws of attraction and rotation, we may find interesting evi- 

 dences of the unity of force which all modern discovery tends to 

 demonstrate, and in that unity a sufficient explanation of the ob- 

 served annual and secular variations of the magnetic needle, the 

 disturbing magnetic effects of auroras and solar spots, the changes of 

 the wind, and storms of every kind. Some of the well-known pheno- 

 mena of storms furnish a ready test of the principles I have attempted 

 to establish. 



Although Fig. 2 represents the general tendency of a particle of 

 air, it is not probable that all the atmosphere, or even, perhaps, any 

 considerable portion of it, follows so regular a path. In the upper 

 regions, where the air is not so much affected by the radiation of 

 the earth, it may oscillate, as suggested by Redfield, " from centrifugal 

 action towards the equator, and gravitation towards the poles,"* and 

 between the points of decussation there are undoubtedly eddies which 

 have a general movement eastward or westward, in accordance with 

 the theory of M. Dove. These f i c, 3. 



several currents are represent- 

 ed in Fig. o. The disturb- 

 ances of the aether, depend- 

 ent upon the relative attrac- 

 tions of the earth and sun, 

 probably produce tides corresponding in time with those of the baro- 

 meter, which must modify the atmospheric currents. The character 

 of these disturbances may be fig -n 



inferred from Fig. 4, the ho- ^ — ^ Z^ — ^ 



rizontal arrows representing the ^ ■^'^^ ~~~^ %^ ^ 



course of the asther under the / / a ^^ ^ ^ 



I I V ^^ / / / 



solar influence, and the curved ^ ^ ^"^JJ J - *■ 



arrows its course under the — 3^ \^^ '"^ ^^^ ^ 



combined attraction of the — ^ ^ *" 



earth and sun. 



Having thus ascertained the causes and directions of the principal 

 normal currents, the ordinary theory of winds enables us to understand 

 the effect of mountain peaks, deserts, forests, rivers, and ocean- 

 streams. Every point of the earth's surface that accumulates or 

 radiates an undue amount of heat, becomes a centre of polarity with 

 an attractive energy that disturbs the atmospheric equilibrium, tend- 

 ing to produce wind and rain. If the disturbance is confined to a 



* Silliman's Journal, vol. 25, p. 130. 

 VOL. IX. — 2x 



^ _ _> _^ ^ 



