562 REPORT— 1888. 



comparable with the size of the vortices than at the distancea at which we study 

 the simple phenomena of electro-magnetism. Indeed, if vortices can make a small 

 piece of a strong elastic solid we can malre watches and build steam engines and 

 any amount of complex machinery, so that complexity can be no essential difficulty. 

 Similarly the instantaneous propagation of gravity, if it exists, is not an essential 

 difficulty, for vortices each occupy all space, and they act on one another simul- 

 taneously everywhere. The theory that material atoms are simple vortex rings in a 

 perfect liquid otherwise unmoving is insufficient, but with the innumerable possi- 

 bilities of fluid motion it seems almost impossible but that an explanation of the 

 properties of the universe will be found in this conception. Anything purporting 

 to be an explanation founded on such ideas as ' an inherent property of matter to 

 attract,' or building up big elastic solids out of little ones, is not of the nature of an 

 ultimate explanation at all ; it can only be a temporary stopping-place. There are 

 metaphysical grounds, too, for reducing matter to motion and potential to kinetic 

 energy. 



These ideas are not new, but it is well to enunciate them from time to time, and 

 a presidential address in Section A is a fitting time. Besides all this it has become 

 the fashion to indulge in quaint cosmical theories and to dilate upon them before 

 learned societies and in learned journals. I would suggest, as one who has been 

 bogged in this quagmire, that a successor in this chair might well devote himself to 

 a review of the cosmical theories propounded within the last few years. The 

 opportunities for piquant criticism would be splendid. 



Keturning to the sure ground of experimental research let us for a moment con- 

 template what is betokened by this theory that in electro-magnetic engines we are 

 using as our mechanism the ether, the medium that fills all known space. It was 

 a great step in human progress when man learnt to make material machines, when 

 he used the elasticity of his bow and the rigidity of his arrow to provide food and 

 defeat his enemies. It was a great advance when he learnt to use the chemical 

 action of fire ; when he learnt to use water to float his boats and air to drive them ; 

 when he used artificial selection to provide himself with food and domestic 

 animals. For two hundred years he has made heat his slave to drive his machinery. 

 Fire, water, earth, and air have long been his slaves, but it is only within the last 

 few years that man has won the battle lost by the giants of old, has snatched the 

 thunderbolt from Jove himself and enslaved the all-pervading ether. 



The following Report and Papers were read : — 



1. Fourth Report of the Committee for promoting Tidal Observations 

 in Canada. — See Reports, p. 27. 



2. On the Behaviour of Water under great Provocation from Heat. 

 By Professor W. Ramsav, F.B.S. 



3. On the Proof of the Logarithmic Laiv of Atomic Weights. 

 By Dr. G. Johnstone Stonet, F.B.S. 



4, On the Oscillations of a Boiating Liquid Spheroid and the Genesis of the 

 Moon. By A. E. H. Love, B.A. 



Riemann's investigations of the motion of a liquid ellipsoid ' contain the con- 

 dition of stability of the form of steady motion, usually referred to as ' Maclaurin's 

 spheroid,' when the liquid is perfectly inviscid. The equation for the critical value 

 of the eccentricity of the spheroid is — 



e (3 + 4e-) ,/T^^= (3 + 2e" - Ae*) sin-\ 

 ' Ahh. Eon. Ges. Wiss. Gottingcn, 1860. 



