SCIENCE IN THE INDUSTRIAL WORLD 



"Some may, perhaps, think that although the elec- 

 tric fire has not been observed to diminish sensibly in its 

 progress through any length of wire that has been tried 

 hitherto, yet as that has never exceeded some thirty 

 or forty yards, it may be reasonably supposed that in a 

 far greater length it would be remarkably diminished, 

 and probably would be entirely drained off in a few miles 

 by the surrounding air. 



"To prevent this objection, and save longer argu- 

 ment, lay over the wires from one end to the other with 

 a thin coat of jeweller's cement. This may be done for 

 a trifle of additional expense, and, as it is an electric 

 per se, will effectually secure any part of the fire from 

 mixing with the atmosphere. I am, etc., C.M." 



EARLY EXPERIMENTS 



Following this proposal, various telegraphs were in- 

 vented, most of them too complicated or too visionary 

 to be of any possible practical importance. Galvanic 

 electricity had not as yet been discovered and the static 

 electricity then available was most erratic and uncertain 

 in its action. Nevertheless by the end of the century, 

 the time of the discovery of galvanism, such progress had 

 been made by numerous inventors that an electric 

 telegraph, fulfilling at least one of the essential condi- 

 tions, that of being capable of transmitting definite 

 messages, had been devised. Of the various ones that 

 of the Spaniard, Don Francisco Salva, who announced 

 his invention to the Academy of Science of Barcelona 

 in December 1795, was perhaps the most important and 

 interesting. 



[8] 



