26 Journal of the Mitchell Society [Septei)iher 



Irons, atoms and molecules, — while if the bod}' itself is in motion an 

 additional mass is given to it in the direction of motion. A shell 

 weighing one ton will have an additional mass of one-millionth of a 

 gram when fired with a muzzle velocity of 2,500 feet per second. For 

 small speeds, therefore, the increase of mass is inappreciable, but for 

 speeds of more than 100,000 miles per second the mass rapidly in- 

 creases until at the velocity of light, which is 186.000 miles per sec- 

 ond, the mass of a body would be infinite. The electrons inside an 

 atom, and the rays fired off from radium, do actually reach prodigious 

 velocities, — more than 100,000 miles per second. 



But if mass is a function of velocity it is not a fundamental quan- 

 tity, and cannot have an independent existence, so it must be given 

 up as one of the pillars of the temple of science. Now comes Rela- 

 tivity and shows that determinations of both length and time also de- 

 pend upon velocity, so they do not have an independent existence 

 either, and two more pillars of the temple fall, irretrievably', because 

 the determination of absolute velocity is forever beyond our reach. 



Thus we have our first experience with the realm of Relativity, — 

 the land of Topsyturvydom. "We have our three fundamental concep- 

 tions of Length, Mass and Time all depending upon a derived concep- 

 tion. Velocity, which we formerly held to be dependent upon them ! 

 And then, having pointed this out, the relativist quietly states that 

 all such experiments as that of Michelson and Morley are bound to 

 fail, because it is impossible to determine the absolute velocity of the 

 earth through the ether by experiments made on the earth, and be- 

 sides, there isn't any ether anyhow! To the first statement we reply 

 that we are on the earth, and can't get anywhere else, so if we cannot 

 determine the velocity of the earth by experiments made here we 

 can never know its velocity, and never be able to fix a unit of absolute 

 motion. To which the relativist retorts, ' ' Quite right, — we never can, ' ' 

 and this is the First Postulate of Relativity. 



To the second statement, that there is no ethereal medium, we can 

 only ask what takes its place, to which the relativist replies, "No 

 medium at all ; electromagnetic energy, including light, is propagated 

 through space somewhat as water is thrown from a hose. It is self- 

 existent, and needs no medium." When we examine this remarkable 

 statement, we should have as the background of our thinking the facts 

 concerning the ether theory, which are, briefly, these: When the as- 

 sumption of the existence of the ether was made, to explain the phe- 



