KNOWLEDGE ♦ 



(t^iiT. 1, 1882. 



in thiso pages— Dr. Sinuens made tbc following reraark- 

 al>K- statements : — 



'•The total annual value of tlie gasworks by-products 

 may l>e estimate*! as follows :— Colourinj,' matter, 

 £3,350.000; sulphate of ammonia, £l,947,Oi'0; pitch 

 (325,000 tons), .l'oG.'<,000 ; creosote (•-'5,000,000 gallons), 

 £■208,000; crude carlKilic acid (1,000,000 gallons), 

 £100,000: gas coke, 4,000,000 tons (after allowing 

 2,000,000 tons consumptiiii in working the retorts), at 

 I •-'.<., £^2,-l00, 000— total, £8,370,000. Taking the coal 

 used, 9,000,000 tons, at I'Js., c-jual £5,400,000, it follows 

 that the by products exceed in value the coal used by very 

 nearly £3,000,000. In using raw coal for heating pur- 

 poses these valuable products are not only absolutely lost 

 to us, but in their stead we are favoured with those semi- 

 gaseous by-products in the atmosphere too well known to 

 the denizens of London and other large towns as smoke. 

 Professor Roberts has calculated that the soot in the 

 pall hanging over London on a winter's day amounts 

 to fifty tons, and that the carbonic oxide, a poisonous 

 compound, resulting from the imperfect combustion 

 of coal, may be taken as at least live times that 

 amount. ilr. Aitken has shown, moreover, in an in- 

 teresting paper communicated to the Royal Society of 

 Kdinburgh last year, that the fine dust resulting from 

 ilie imperfect combustion of coal is mainly instrumental 

 in the formation of fog, each particle of solid matter 

 attracting to itself aqueous vapour ; these globules of fog 

 are rendered particularly tenacious and disagreeable by the 

 presence of tar vapour, another result of imperfect combus- 

 tion of raw fuel, which might be turned to much better 

 account at the dye-works. The hurtful influence of smoke 

 upon public health, the great personal discomfort to which 

 it gives rise, and the vast expense it indirectly causes 

 through the destruction of our monuments, pictures, furni- 

 ture, and af>par»;l are now Ijeing recognised, as is evinced 

 by the success of recent Smoke Abatement Exhibitions. 

 The most effectual remedy would result from a general 

 recognition cf the fact that wherever smoko is produced 

 fuel is l»eing consumed wastefully, and that all our calorific 

 etlects, from the largest down to the domestic fire, can be 

 realised as compleUdy, and more economically, without 

 allowing any of the fuel employed to reach the atmosphere 

 unburnt This most desirable result may be etlected by 

 the use of gas for all heating purjjoscs with or without the 

 addition of coke or anthracit<^\" 



We must not pa.ss over references to the probable future 

 improvement of our merchant steam shipping by the use 

 of more f>erfect engines (gas-engines, of half the weight of 

 the present, and working with only half the present ex- 

 penditure of fuel) of the new kind of steel (mild steel) 

 introduced 1 y the Admiralty in 1870-78, by which 20 per 

 cent of the weight of a ship's liuU can be saved, of double 

 Ijottoms, and solid bulkheads for the division of a ship's 

 hold. "With such improvements," said Dr. Siemens, "the 

 lialance of advantages in favour of steam vessels (or, rather, 

 prop<.ller vessels) would be sufiicient to restrict the use of 

 sailing craft chiefly to the regattas of Southampton and 

 neighViouring port*." 



After «p<-aking of deep-sea soundings, and recent im- 

 provements therein, Dr. Siemens referred to the proposed 

 means for crofiin;; the Ihthmug of Panama, and the sug- 

 gmied flootlinx "^ '''e Tunis Algerian desert. He spoke 

 of the new Eddy»tone LiKhthotise, and the St. (iothard 

 tunnel, the proposed tunnel lielow the P'nglish Channel, 

 and England's impressive "military anxieties " respecting 

 it After touching on other gul>-pontine works, suggested 

 or in progress. Dr. Siemens cpokc of the improvement of 

 explonive agents, cannon, ic. 



His remarks on the jihenoniena of electric discharges 

 were of considerable interest. " By the discharge cf 

 high-tension electricity through tubes containing highly- 

 rarelicd gases (Geissler's tubes), phenomena of discharge 

 were produced which were at oneo most striking and 

 suggestive. The Sprengd pump allbrded a means of 

 pushing the exhaustion to limits which had formerly 

 been scarcely reached by the imagination. At each 

 step the condition of attenuated matter revealed vary- 

 ing properties when acted upon by electrical discharge 

 and magnetic force. The radiometer of Crookes imported 

 a new feature into these imiuiries, which at the present 

 time occupy the attention of leading physicists in all coun- 

 tries. The means usually employed to produce electrical 

 discharge in vacuum tubes was Ruhuikorir's coil ; but Mr. 

 Gassiot first succeeded in obtaining the phenomenaby means 

 of a galvanic battery of 3,000 Leelnnclio cells. Dr. De La 

 Rue, in conjunction with his friend Dr. Hugo Miillor, has 

 gone far beyond his predecessors in the production of bat- 

 teries of high potential. At his lecture 'On the Phenomena 

 of Electric Discharge,' delivered at the Royal Institution in 

 January, 1881, he employed a battery of his invention 

 consisting of 14,400 cells (14,832 volts), which gave a 

 current of 054 ampere, and produced a discharge at a 

 distance of 71 inch between the terminals. During last 

 year he increased the number of cells to 15,000(15,450 

 volts), and increased the current to 1 amp6re, or eight 

 times that of the battery he used at the Royal Institution. 

 On the occasion of his lecture, Mr. Do La Rue produced, 

 in a very large \acuuni tube, an imitation of the aurora 

 borcalis ; and he has deduced from his experiments that the 

 greatest brilliancy of aurora displays must be at an altitudt> 

 of from thirty-seven to thirty-eight miles— a conclusion of 

 the highest interest, and in opposition to the extravagant 

 estimate of 281 miles at which it had.bcen previously put." 

 It was hardly to be expected that the eminent electrician 

 should not make an attempt to galvanise into the semblance 

 of life his defunct theory of the conservatism of solav 

 energy. In some way peculiar to the inventors of in>- 

 possiblc theories, he finds evidence for his speculations 

 where others recognise decisive (though in this case little 

 needed) evidence against it. The long extensions of the 

 corona not far from the equatorial regions, seen during tho 

 American eclipse of 1878, if constantly visible, would cor- 

 respond with the theory. But if th(! theory were true, 

 they should be always visible. During the Egyptian, 

 eclipse last May they were absent ; but " No matter," Dr. 

 Siemens thinks ; "the outflowing equatorial streams I sup 

 pose to exist could only be rendered visible l)y reflected 

 siinlinht, when mixed with dust produced by excc^ptional 

 solar disturbances, or by electric discliarge ; and the occa- 

 sional appearance of such luminous extensions would serve 

 only to disprove the hypothesis entertained by some 

 that they are divided planetary matter, ^ in which casfr 

 their apjiearance should be permanent "—it being, he- 

 might as soundly have added, a well-known pro- 

 p(;rty of planetary matter to remain permanently at 

 rest.* "Stellar space filled with such matter as hydro- 

 carbon and aqueous vapour would estaljlish a material 

 continuity between the hun and his planets, and betweeu 



• The nrgumont is this : If tlicro were Uio oODBUnt Btrcumi'rK- 

 forth from tho oqnivtor imagined l.y Ur. KicmcnB, the oqimtorial 

 BtroaiiiH Hhould alwnys bo there. If there is oosmical dust travel- 

 liiiB round and about tho sun in orbits of all dogroes of eccentricity, 

 not only would eclipscB ocen in different monthH differ much inter 

 .«— but owing to tho conHlant motion of the cosmic matter, bo alflo 

 would cclipHCB seen in dilTcrcnt ycarB in tho same month. Ur. 

 Sicmong think* just the rover«e doubtlcsB liaving Bomo ronHoni'. 

 Unfortunately he ODiitH to mention tliem. 



