51 



own study of the subject that correspondences of 

 earthquake phenomena may take place in direct 

 relation to the moon's position in her orbit. But 

 the method of accounting for the phenomena on 

 the tidal theory, I do not agree with. I think 

 all volcanic phenomena are produced by molecu- 

 lar repulsive force exerted from the centre of the 

 globe to its periphery to resist the nearer ap- 

 proach of the moon to the earth — and nearer 

 approximation of the earth to the sun. In my 

 •'Cosmography - ' I showed the greater frequen- 

 cy of earthquake phenomena during the passage 

 of the earth through the perihelic portion of 

 its orbit — and on the well established astronomi- 

 cal and physical tact that planets increase in den- 

 sity in an inverse ratio to their distance from the 

 solar centre. 



I advanced the opinion that the density of the 

 individual planets and of the numerous, revolving 

 spheres varied during their respective' orbitual 

 periods in an inverse proportion to their distance 

 from their central body. This variation of den- 

 sity could not take place without molecular 

 expansion and contraction, or variation of dis- 

 tance between the molecules, and as a necessary 

 consequence the whole mass of the planetary 

 sphere would contract and expand more or less 

 (though on the whole very little, in solid globes, 

 on account of the fixed law determining their 

 density,) or rather the forces necessary to pro- 

 duce expansion and contraction would be ex- 

 erted, which end in the phenomena transpir- 

 ing on the surface of our globe, such as the 

 elevations and depressions of continental a- 

 reas, earthquake shocks by rupturing of the 

 crystalline crust and injection of lava through 

 solid igneous rock, and between sedimentary stra- 

 ta, thereby producing the various motions, hereto- 

 fore inexplicable, attending volcanic convulsions 

 as the gyratory movements which result natural- 

 ly from the circular injection of prodigious whirl- 

 pools of lava between strata, or into immense 

 fissures at greater or less depths below the unbro- 

 ken surface-crust. — the outpourings of lava from 

 volcanic openings, and the remarkable simultane- 

 ousness and universal occurrence of all sorts of 

 earthquake phenomena throughout the globe ; 

 also the varying intensity of movements of the 

 compensating pendulums; also, such as the 

 variation of the pressure of the ocean and its pe- 

 riodical shrinkage and expansion, which will 

 be proven to tele place when more 

 careful observations have b sen madeon tides, and 

 which phenomena will be found , ot to depend on 

 atmospherical pressure, us is supposed by Sir 

 in his paper read to the Royal 

 Society of London, in June 1854 ; such as also 

 the periodical variation of atmospherical pres- 

 tore, sufficient observations on which have b 

 dy been made to establish the fact, and. as I 

 belfeve from my study of them, to show ae con- 



clusive and regular variations of atmospheric 

 pressure as are now known to exist in the annual 

 variations of the magnetic needle. Even these 

 annual, periodical and regular variations of 

 declination of the magnetic needle, in other words 

 the variations of atmospheric electricity or mag- 

 netic intensity at the surface of the earth, well 

 known now by observation, not to depend on 

 barometrical circumstances, but which annu- 

 ally increase and diminish according to the posi- 

 tion of the earth in the perihelic and aphelic 

 portions of its orbit, I believe to depend on the 

 molecular motions — or the play of molecular 

 forces, which transpire to produce the annual 

 increasing: and diminishing density of the globe 

 and which molecular forces and motions take 

 place throughout the sphere from the centre to 

 the circumference of the entire surface of the 

 earth. The variations of these electrical or mag- 

 netic phenomena, occurring so regularly periodi- 

 cal, have been supposed by physicists to only 

 exist in the atmosphere, either in its lower or upper 

 regions, and to have been derived from the sun 

 by induction, whereas, I think from a profound 

 study of this subject, that they are produced 

 within the globe by the more or less intense mo- 

 tion of, or action in the lines of molecules which 

 in all directions extend from every point on the 

 surface of the globe, through the terrestrial cen- 

 tre to its antipode, and the motion in these is 

 constantly taking place by virtue of the inherent 

 forces of attraction and repulsion in each mole- 

 cule, which forces are exerted not only to preserve 

 the law of density fixed for this planet by its po- 

 sition in space, but to maintain the form and po- 

 sition of the planet in its permanent relation to 

 the sun on the one hand as its source of power 

 and excitement, and to the moon on the other, 

 as a dependent on its radial forces of attraction 

 and repulsion. In other words, cosmical magnet- 

 ism is a planetary force produced by the constant- 

 ly varying intensity of the forces of the molecules 

 which in the aggregate constitute the planetary 

 masses; and terrestrial magnetism, as a conse- 

 quence, is a power radiating from every point of 

 the globe, and generated within it in consequence 

 of its orbitual relations to the solar centre, its 

 orbit being an ellipse, aud the sun fixed in one of 

 the foci of that ellipse, whereby it being at dif- 

 ferent distances from the sun at different periods 

 of the year, the number and intensity of terrestri- 

 al phenomena of all sorts transpiring in the air, 

 ocean, solid crystalline crust, and mo ten interior, 

 and in the forces pervading its molecules, differ 

 iccordingly; and. as a consequence of my theory, 

 if all these phenomena are studied by physicists 

 from a different point of view than that from 

 which they have Been heretofore, 1 believe the 

 most remarkable advances in every department, 

 of physical science will be rapidly made, and a 

 new world of knowledge opened to future 



