SIGNALING THROUGH SPACE WITHOUT WIRES. 1 



By W. H. Preece, Esq., O. B., F. R. S., M. Inst. C. E. 



Science lias conferred one great benefit on mankind. It has supplied 

 us with a new sense. We can now see the invisible, hear the inaudible, 

 and feel the intangible. We know that the universe is filled with a 

 homogeneous continuous elastic medium which transmits heat, light, 

 electricity and other forms of energy from one point of space to another 

 without loss. The discovery of the real existence of this "ether" is 

 one of the great scientific events of the Victorian era. Its character 

 and mechanism are not yet known by us. All attempts to "invent" a 

 perfect ether have proved beyond the mental powers of the highest 

 intellects. We can only say with Lord Salisbury that the ether is the 

 nominative case of the verb "to undulate." We must be content with 

 a knowledge of the fact that it was created in the beginning for the 

 transmission of energy in all its forms, that it transmits these energies 

 in definite waves and with a known velocity, that it is perfect of its 

 kind, but that it still remains as inscrutable as gravity or light itself. 



Any disturbance of the ether must originate with some disturbance 

 of matter. An explosion, cyclone, or vibratory motion may occur in the 

 photosphere of the sun. A disturbance or wave is impressed on the 

 ether. It is propagated in straight lines through space. It falls on 

 Jupiter, Venus, the Earth, and every other planet met with in its 

 course, and any machine, human or mechanical, capable of responding 

 to its undulations indicates its presence. Thus the eye supplies the 

 sensation of light, the skin is sensitive to heat, the galvanometer indi- 

 cates electricity, the magnetometer indicates disturbances in the earth's 

 magnetic field. One of the greatest scientific achievements of our 

 generation is the magnificent generalization of Clerk-Maxwell that all 

 these disturbances are of precisely the same kind, and that they differ 

 only in degree. Light is an electromagnetic phenomenon, and elec- 

 tricity in its progress through space follows the laws of optics. Hertz 

 proved this experimentally, and few of us who heard it will forget the 



1 From proceedings of the Eoyal Institution of Great Britain, Vol. XV, Part II, 

 No. 91, April, 1898, pp. 467-476. Read at weekly evening meeting, Friday, June 

 11, 1897. 



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