330 



NATURE 



[February 2, 1893 



the ether, and they are taken up again by matter. One kind 

 of wave gives us light, another radiant heat, another magnetism, 

 and another electrification. The rate at which these waves 

 move is the same, viz. 30,000,000,000 centimetres, or 192,000 

 miles, per second. It is only their form and their frequency 

 that ditTer. Matter and ether are subject to strains, currents, 

 vortices, and undulations, and every single electro-magnetic 

 phenomenon can be compounded of or reduced to one or other of 

 these mechanical disturbances. Rotation in one direction 

 gives positive electrification : rotation in the opposite direction 

 gives negative electrification. A whirl in one direction gives 

 us north magnetism ; in another direction, south magnetism. 

 Hertz, the experimental exponent of Maxwell's views, has 

 shown the existence of electro-magnetic waves, and has proved 

 their reflection, refraction, and interference. The rate of their 

 propagation is the same in ether, air, and conducting wires. 



The most recent discoveries and deductions are all in accord- 

 ance with this mechanical theory. J. J. Thomson's views that 

 at high temperatures, in the act of dissociation, all gases, and 

 Dewar and Fleming's conclusion that at low temperatures — in 

 fact, at the absolute zero of temperature — all metals become 

 perfect conductors, might almost have been predicted. Hysteresis 

 and Foucault losses are mere wastes of energy, due to molecular 

 friction or to internal work done on the molecules, assisted by 

 bad design and impure material ; but, being measurable and 

 comprehensible, their reduction to a minimum has become 

 possible and actual. 



It is a misfortune that a beautiful hypothesis like Maxwell's 

 electro-magnetic theory of light lias been discussed almost solely 

 by mathematicians. Its consideration has been confined to a 

 small and exclusive class. It has not reached the public ; and 

 this is to be regretted, for, after all, it is the many, and not the 

 few, that determine the acceptance or refusal of a theory. The 

 existence of the ether is now thoroughly comprehensible. Light 

 is now regarded as an electro-magnetic disturbance. The eye is 

 an extremely sensitive and delicate electromagnetic instrument. 

 The difference between luminous, thermic, and electro-magnetic 

 waves is one of frequency and form. We thus have to consider 

 the propagation of these waves not only in the conductor and in 

 the dielectric in the direction of the circuit itself, but in the 

 ether at right angles to this direction. The foruier produces 

 currents in the conductor, and the latter induction and secondary 

 effects in contiguous conductors. Thus it is easy to see why 

 electric and magnetic lines of force are at right angles to each 

 other, and each of them perpendicular to the line of propagation 

 of the primary electro-magnetic wave, and why the transversal 

 disturbances are secondary waves of electro-magnetic energy 

 which can be transformed into electric currents of opposite 

 direction whenever contiguous conductors lie in their path so as 

 to be cut by these lines of force in the proper direction. Induc- 

 tion is thus mere transformation of energy whose direction and 

 magnitude are easily calculated. 



It is by following out this line of thought that I have 

 recently succeeded in sending messages by Morse signals across 

 the Bristol Channel between Lavernock and Flat Holm, a dis- 

 tance of 31 miles. The electro-magnetic disturbances were 

 excited by primary alternating currents in a copper wire, 

 1237 yards long, erected on poles along the top of the 

 cliff on the mainland. The radiant electro-magnetic energy 

 was transformed into currents a^ain in a secondary circuit, 

 610 yards long, laid along the island. The strength of these 

 secondary induced currents complied almost exactly with calcu- 

 lations. The results attained, the apparatus used, the pre- 

 cautions taken to separate effects of induction from effects of 

 conduction ; the elimmation of mere earth currents from electro- 

 magnetic disturbances in air, will form the subject of a separate 

 paper, for their proper consideration would be too tedious for an 

 address. I allude to them won only to illustrate the existence 

 of one of the greatest proofs of the truth of a theory, viz. the 

 practical development and verification of a conclusion predicted 

 from mere theoretical considerations. 



The o.-cillatory character of the discharge of a Leyden jar, 

 which was discovered by Henry in 1842, is an admirable 

 proof of this molecular theory. If two jars, precisely similar as 

 regards capacity and circuit inertia, be placed near each other 

 with their planes parallel, and one of them is charged and dis- 

 charged, the other responds sympathetically, as do two similarly 

 pitched tuning-forks when one is excited. Professor Oliver 

 Lodge, who has made this field his own, has shown that by 

 varying the capacity of the jars and the inertia of the circuit, 



NO. 1214, VOL. 47] 



oscillations can be produced to give any required rate of oscilla- 

 tion from one to 300 millions per second. 



In a room or theatre, when these discharges are excited, it is 

 a common thing to see sympathetic sparks upon the spangled 

 walls, and among the metallic objects scattered about. The 

 whole place is an electric field, which is violently disturbed at 

 every spark, and everything which is " syntonised," as Oliver 

 Lodge calls it, to the main discharge, responds in this way. 



It is impossible to account for these effects, which are all cases 

 of transformed kinetic energy, except on the mechanical theory 

 which I have advanced. We have a source of disturbance, we 

 have energy transmitted in waves, we have wave transformed 

 into disturbance again. Energy passes through its various stages 

 by the motion of matter and the action of the ether. Every- 

 thing is accounted for and nothing is lost. Waste energy only 

 means energy in the wrong place. 



YEZO AND THE AINU. 



T^ 



wo papers on recent travels in the Island of Yezo were read 

 to the Royal Geographical Society on Monday evening. 

 Prof. J. Milne, F.R.S., whose paper was read by the Secretary, 

 made a journey to the north-east of the island by sea in 1891, and 

 returned by land, crossing Yezo almost through its centre. He 

 was accompanied by Mr. John Revilliod, and travelled with a 

 view to studying the volcanic geology of the regions. Landing at 

 Kushiro, interesting on account of the relics of pre- Ainu inhabit- 

 ants, and on account of its coal mines, they ascended the Kusuri 

 river to Shibecha, where there is a great convict prison and 

 sulphur refinery, the raw sulphur being obtained from the vol- 

 cano Atosanobori, to which there is a railway twenty miles long. 

 In this locality the violence of the escape of steam from the boil- 

 ing springs exceeds anything seen elsewhere in Japan, New 

 Zealand, or Iceland. A new road, thirty-seven miles long, led 

 from the volcano to Apashiri, on the north-east coast, where a 

 factory for making matches has recently been erected, on account 

 of the abundance of the white-stemmed poplar, the timber of 

 which is much more readily worked in the fresh state than when 

 dried. A boat journey was made in a small dug-out canoe under 

 rugged cliffs from 500 feet to 1000 feet in height, for thirty miles 

 to Shiritoki, where there is a great sulphur mine. From some 

 of the volcanic craters fused sulphur flows like lava, and crystal- 

 lises in an almost pure state. A trip from Nemuro to the nearer 

 Kurile Islands was followed by the main feature of the journey, 

 a ride from Yubets, on the north coast, up the Yubets river, 

 across the watershed, and down the Ishikari river, to the west 

 coast. Groups of convicts working on the new roads, which are 

 being made across the island, were almost the only people met 

 with. Vast groves of tall bamboo grass everywhere impeded 

 the travellers, and insects of all kinds proved very troublesome. 

 There was little or no sign of larger animal life. 



Mr. A. H. Savage Landor also read a paper. He had 

 wandered all round Yezo and up several of the largest rivers 

 quite alone, and with no object save curiosity and the desire to 

 study the Ainu at home. The main part of his equipment was 

 a great store of painting material, of which he made good use 

 in portraying both the natives and the scenery of the island. 

 The Ainu accessible from Hakodate, who have been frequently 

 visited and often described, are almost all Japanese half-breeds, 

 and much influenced in customs and costume by their southern 

 neighbours. The Ainu of the interior and the more distant 

 parts of the coast were very different. The true Ainu villages 

 are intensely filthy, and the vermin in them make life almost 

 unsupportable to a stranger, minute black flies, which swarm in 

 incredible hosts, being the worst. The people, although good- 

 humoured, are sunk in the most degraded savagery. Their 

 marriage customs seem to be summed up in unqualified 

 promiscuity, the Ainu disclaiming any idea of being better than 

 bears or dogs. The Ainu language is poor in words, and 

 many of them show a curious resemblance to words of Anglo- 

 Saxon origin, e.g. Chip, for ship ; Do, day ; Mukku, music ; 

 Pone, bone ; Ru, road ; To, two ; Wakka, water. The religious 

 beliefs of the Ainu can hardly be dignified by such a term ; they 

 are merely superstitions. In travelling along the south-west 

 coast there was often considerable danger from the waves 

 washing over the narrow track which wound between the 

 boulders on the beach. Fog prevails along the east coast in 

 summer, probably on account of the Kuro-Siwo encountering a 

 cold current off the island. The upper Tokachi river was the 



