Dolbear.] 
188 
[ Jan. 21 , 
characteristics of motion. The only theory of matter that has any 
degree of probability now, is the vortex-ring theory proposed by 
Sir Wm. Thomson, that considers an atom as being a vortex- 
ring of ether, in the ether. 
The ease with which such an atom lends itself to the explana- 
tion of physical phenomena is surprising, and leads one to the 
reflection that if it is not true it ought to be, as some one once 
said concerning the nebula theory. So far as the phenomena 
alone are concerned it makes not much difference for present pur- 
pose whether this or some other form be adopted, but for conven- 
ience I shall adopt the vortex ring as the typical atom, therefore 
having a ring structure and the possibilities of harmonic vibratory 
motion, thus. fig. 1. This change of form con- 
stituting what is called heat, and the am- 
jar plitude of which is the measure of the tern- 
fm perature of the atom. Given such an 
l ft jB/ atom vibrating in a harmonic motion as 
Jw' represented, it is seen that there are what 
in acoustics are called nodes and loops, 
fig. i. places of greatest and least amplitude of 
vibrations, four of each. If it be borne in mind now that this is 
the motion that is handed over to the ether and becomes ether 
waves, it will be seen that the rate at which such energy is trans- 
ferred at a given point must depend upon the amplitude of vi- 
bration at that point. At the points of maximum vibration it 
must be greatest, and least at the nodes, and hence the space 
adjacent to a loop must be in a different physical condition from 
that adjacent to a node, and such changed relations must be 
symmetrical with reference to the vibratory body. 
Guthrie discovered a good many years ago that a vibrating tun- 
ing fork apparently attracted other bodies near to it, and Thom- 
son explained the phenomenon as due to the lessening of the 
density of the medium about the prongs of the fork, the density 
being least when the amplitude was greatest. Guthrie thought 
by this means he could explain gravitation, as being due to the 
vibration of atoms. This idea implies that gravitation should de- 
pend upon temperature which I hardly need say is unwarrantable. 
If, however, there be an atomic phenomenon that is known to 
depend upon temperature, it would be quite to the point to apply 
such relation and see how far such an explanation will go in ac- 
counting for the observed phenomena. How a vibrating body 
