Prof. Norton on Molecular Physics. 281 



tion we have given of the progressive change of declination. 

 Dr. Lloyd, in his discussion of the Dublin Observations (between 

 1840 and 1843) , has established that the needle at Dublin has, 

 from the vernal equinox until after the summer solstice, a mo- 

 tion in a direction opposite to the annual progression, and a 

 motion in the other direction from the autumnal to the vernal 

 equinox. The discussions of the observations at Philadelphia 

 and Toronto have revealed a similar law at those stations, though 

 the direction of the annual progression is reversed. Now at 

 Dublin the new currents developed at all seasons tend to give 

 the needle an easterly deflection, except near the autumnal 

 equinox, when their effect upon the declination will be slight. 

 For the currents will run from S. of the magnetic E. to N. of 



of space (p. 2/0). The penetration of cosmical matter into the photosphere 

 is another source of heat. 



2. Similar inferences may be drawn with respect to the magnetic and 

 thermal condition of the . planets ; and an approximate estimate may be 

 made of the comparative condition of the different bodies of the solar 

 system. 



3. The continual development of heat in the entire mass of the earth, 

 by the action of the aether, is probably the origin of those subterraneous 

 titanic forces which have so repeatedly, in past geological ages, fractured 

 and upheaved certain portions of the earth's crust, and whose effects are 

 now observable in earthquakes and volcanic eruptions. Upon this idea 

 there should probably be certain lines of upheaval corresponding to the 

 magnetic currents in some of their shifting and comparatively stationary 

 positions. 



4. The rotating and revolving nucleus of a comet should become mag- 

 netized and heated in the same manner as the earth and the sun, both in 

 its mass and photosphere. In this fact we have the apparent origin of the 

 formation and detachment of successive nebulous envelopes, and of the 

 emission of luminous jets from the nucleus, the process of detachment 

 and indefinite expulsion being the same as already alluded to as in opera- 

 tion in the photosphere of the earth (p. 280). The same process attends 

 the formation of the solar spots, and originates streams of nebulous matter 

 seen in the zodiacal light. The residual cometary phenomena which 

 remain unaccounted for by Olbers and BesselY theory, as applied and am- 

 plified by the author (see Silliman's Journal, vols, xxvii., xxix., and xxxii. 

 [2]), may be understood, in their minute details, in the light of the present 

 conception. 



5. It may be added in confirmation of the theory of the continual descent 

 of auroral matter, derived from the sun, into the earth's photosphere, that 

 the diurnal variations of the electric tension near the earth's surface are in 

 accordance with the idea that free atmospheric electricity, for which no 

 adequate terrestrial cause has yet been ascertained, is derived from the 

 auroral matter thus received. Also the diurnal variations of the barometer 

 are other observed effects that should result, on mechanical principles, 

 from the same general cause. 



Again, the diminution in the hourly fall of the temperature during the 

 latter part of the night, for which no sufficient meteorological cause can be 

 found, would seem to afford direct evidence of the heating effect that has 

 been attributed to the resisting impulses received from the aether of space. 



