OF ARTS AND SCIENCES. 83 



constantly a current in one way down the hill, and the sputtering of 

 the telephone is sometimes so great, when every thing is quiet out of 

 doors, as to attract attention anywhere in the room. I have several 

 times observed the effect of a thunder-storm upon the line. Generally 

 it happens that before the shower there is nothing to be heard, even 

 though the lightning is only three or four miles away ; but while 

 the shower is overhead, the discharges are sometimes so loud from 

 the telephone as to be heard upstairs in my house. And after the 

 shower has passed a long way off, so far that the thunder cannot be 

 heard at all, every flash has a response in my telephone. 



A close wound spiral of steel wire was made fast by one end to the 

 middle of the vibrating plate, and the other end to a post seven or 

 eight inches back of it. Within this helix a permanent magnet was 

 so placed as not to touch the coil in any place. It was reasoned that 

 this arrangement should also give sonorous results, as the vibrations of 

 the plate would move the spirals of the coil to and fro across the 

 magnetic field, and thus give rise to corresponding currents in the cir- 

 cuit. This was found to be true ; but the results were unsatisfactory, 

 and nothing articulate was heard from it, though some other sounds 

 were. This was also tried by incorporating a battery in the circuit, 

 but with no different results. 



A great many experiments were also tried with the view of finding 

 whether the passage of a sound -vibration through an electric con- 

 ductor would in any way affect the current, to break it up into cor- 

 responding pulsations. To this end, batteries of varying elements and 

 strength were coupled to my line, and vibrations set up in the line-wire 

 in various ways, such as by striking, by drawing a resined bow across 

 it, by tying the string telephone to it and making sounds of varying 

 pitch : in none of these was there any observed effects. 



Another variation in this experiment was to let a person take the 

 two terminals in a circuit including a battery and a receiving telephone, 

 and, while thus being a part of the circuit, singing and talking in the 

 endeavor to discover if such agitation from sounds as can plainly be 

 felt by one would produce any undulations in the circuit. No such 

 effects were noted. 



Three telephones were included in one circuit ; two of them close 

 together, the third at a distance. Sounds were produced in the two ad- 

 jacent ones. It was thought to be possible that the electric waves might 

 neutralize each other if they were sent in opposite directions, if the 

 two had the same intensity, thus furnishing a means of measuring the 

 intensity of sounds ; but no such interfering results were noticed. 



