350 ABSTRACTS OF SCIENTIFIC PAPKRS 



had taken place in almost all failures where the cable itself had not 

 been broken. 



VIII. Report on Electrical Instruments. 'Jurors' Report on the 

 International Exhibition, London, 1862.' 



The Report describes and discusses the exhibits under the 

 following heads : I. Introduction. II. The Construction of Tele- 

 graphic Lines. III. Instruments employed in the Transmission of 

 Messages. IV. Philosophical Instruments, or Instruments used in 

 Experimental Research. V. Practical Applications of Electricity 

 other than Telegraphic. Chapter II. contains comprehensive sta- 

 tistics of submarine cables laid up to the date of the Report. 



The following sentences may be quoted from the Introductory 

 chapter for the sake of their historical interest : 



' The electrical instruments now exhibited are numerous and 

 excellent, whereas, in 1851, the Jury Report states that they were 

 but few in number. . . . The past eleven years have not been 

 marked by any great discovery in electrical science, nor by any very 

 important novelty in the practical application of its principles. We 

 have to register no such marvellous invention as the electric telegraph 

 nor any new motive power superseding steam. On the contrary, it 

 must be acknowledged that many sanguine anticipations in this 

 direction remain unfulfilled. We have on the other hand to record 

 a great extension of the telegraphic system, and especially the intro- 

 duction of submarine cables. . . . The absence of useless though 

 specious inventions is illustrated by the fact that electromotors, or 

 machines for the production of motive power by the voltaic current, 

 are few in number and quite unimportant. The researches of Dr. 

 Joule have shown that with the present prices of materials it would 

 be utterly vain to expect that the power to be obtained from the 

 conversion of zinc into its sulphate should compete economically with 

 that resulting from the combustion of coal. Let a battery be in- 

 vented in which a cheap material only is consumed, and it will then 

 be time to consider which is the best arrangement for converting the 

 voltaic current into mechanical effect. 



' One by one the causes of failure [in submarine cables] have been 

 discovered and eliminated, with such success that the cables lately 

 laid have thus far been uniformly successful. The electrical tests 

 have especially been brought to great perfection, and indeed these 

 researches into the electrical properties of the materials used as con- 

 ductors or insulators, and into the phenomena accompanying the 

 transmission of signals, have been prosecuted with such diligence and 



