284 THE ADDRESSES, LECTURES, ETC., OF 



it the subject of a Friday evening lecture at the Royal Institution. 

 These two circumstances combined obtained for me an entry into 

 scientific circles, and helped to sustain me in difficulty until, by 

 dint of a certain determination to win, I was able to advance step 

 by step up to this place of honour situated within a gunshot of 

 the scene of my earliest success in life, but separated from it by 

 the time of a generation. But notwithstanding the lapse of time, 

 my heart still beats quick each time I come back to the scene of 

 this, the determining incident of my life. 



At the time I am speaking of, the electric telegraph was 

 occupying the minds of the philosophers of different countries, but 

 it was not until the year 1846 that the first practical line of 

 telegraph was established between Paddington and Slough, where 

 it soon gained notoriety in preventing the escape from justice of a 

 great criminal. It is unnecessary for me to insist upon the 

 enormous results that have been achieved by this great modern 

 innovation, which goes even beyond the poetic vision of Shake- 

 speare himself, who in the extravagance of his "Midsummer 

 Night's Dream" makes Puck "encircle the earth in forty 

 minutes," a rate of communication which would nowadays hardly 

 satisfy the City merchants who expect Calcutta and New York to 

 respond to their calls much more promptly than that. 



The telegraph has found its simplest but most remarkable 

 development in the telephone, which although shadowed forth by 

 Riess in 1862, was only reduced to anything like a practical shape 

 by Graham Bell in 1876, and subsequently extended by Edison, 

 Hughes, and others. 



This latter invention appeared at first particularly unpromising 

 of practical results. The currents set up through the vibrations 

 of a metallic diaphragm facing the poles of a magnet are so feeble, 

 and the rate of succession of currents necessary to produce sound 

 (represented by 440 vibrations per second to produce the note 

 fundamental la) was so very much beyond anything met with in 

 telegraphy, that it was difficult to conceive how such a succession 

 of distinct currents with the infinite variety of strength and 

 quality necessary to reproduce speech, could be transmitted 

 through a line wire many miles in length, and could reproduce 

 mechanically the same sounds at the receiving end. Yet the 

 telephone has become a practical reality, and its ultimate powers 



