DISCOURSE OF W. B. TAYLOR. 245 



of detailing to him his own similar combination of two electro- 

 magnetic circuits, experimentally tried more than a year previously.* 



Nearly a year was employed in foreign travel, most pleasantly 

 and beneficially both for mind and body: the greater portion of the 

 time however being spent in London, in Paris, (where Henry 

 formed the acquaintance of Arago, Becquerel, De la Rive, Biot, 

 Oay-Lussac, and other celebrities,) and in Edinburgh, where he also 

 found a galaxy of eminent and congenial minds. 



In September of the same year (1837) he attended the meeting 

 of the British Association at Liverpool ; where being invited to 

 speak, he made a brief communication on some electrical researches 

 in regard to the phenomenon known as the " lateral discharge :" — a 

 study to which he had been led by some remarks of Dr. Roget on 

 the subject. "The result of the analysis was in accordance with an 

 opinion of Biot — that the lateral discharge is due only to the escape 

 of the small quantity of redundant electricity Avhich always exists 

 on one side or the other of a jar, and not to the whole discharge." 

 Hence we could increase or diminish the lateral action by any means 

 which affect the quantity of free electricity : — as by " an increase 

 of the thickness of the glass, or by substituting for the small knob 

 of the jar, a large ball. But the arrangement which produces the 

 greatest effect is that of a long fine copper wire insulated, — parallel 

 to the horizon, and terminated at each end by a small ball. When 

 sparks are thrown on this from a globe of about a foot in diameter, 

 the wire at each discharge becomes beautifully luminous from one 

 end to the other, even if it be a hundred feet long : rays are given 

 off on all sides perpendicular to the axis of the wire :" — forming a 

 continuous electrical brush. It was also stated "that the same 

 quantity of electricity could be made to remain on the wire, if grad- 

 ually communicated [by a point] ; but when thrown on in the form 

 of a spark, it is dissipated as before described :" — as though possess- 

 ing a kind of momentum. When two or more wires are arranged 

 in parallel lines (in electrical connection), only the outer sides of the 



*" I informed him that I had devised anotlier method of producing efTects some- 

 what similar: tills consisted in opening the circuit of my large quantity magnet at 

 Princeton, when loaded with many liundred pounds weight, by attracting upward 

 a small piece of movable wire with a small intensity magnet connected with a long 

 wire circuit." (Henry's Deposition in the case of 6'Rielly and Morse, September 

 7, 1849.) 



