708 



TELEPHONE. 



TENNESSEE. 



encr, reproduce the original sonnd or voice. The 

 arrangement being the same at both ends, the 

 machine, of course, works both ways; so that 

 when a person is talking to the distant dia- 

 phragm the direction is reversed, and the sounds 

 are emitted by the diaphragm near by, and thus 

 the original talker gets his response. 



To make a telephone, procure a tube, b b 

 (Fig. 4), of thin sheet-brass, one inch long, two 

 inches in diameter, and with a flange one-halt' 

 inch wide. Then from a ferrotype-plate the 

 photographer's " tin-type " cut a round plate, 

 shown edgewise at c c, to cover the tube b b 

 over the flange. This is the vibrator or dia- 

 phragm. Next cut a wooden ring or " wash- 

 er," d d, the width of the flange, and about 

 one-eighth of an inch thick. Then make a 

 spool, e e, one inch long, of thin sheet- brass 

 again, with one flange wide enough to cover 

 the wooden ring, the tube of the spool being 

 made so as to fit tightly the magnet </, which 

 is a strongly-magnetized steel rod, four inches 

 long and three-eighths of an inch in diameter. 

 The parts will then fit together, and may be 

 screwed firmly through the flanges b b. The 

 least polished side of the plate c c should face 

 the magnet, and it is well to scrape the part 

 opposite the end of the bar, so as to expose the 

 iron. The spool is to be wound with about 

 fifty yards of No. 36 or 38 silk-covered copper 

 wire, about the thickness of a bristle. The 

 magnet is then shoved in, till it nearly touches 

 the plate c e. After joining the ends of the 

 spool-wire to the line-wires ff, that run to 

 another instrument just like it, the telephone 

 will be ready for use. It is important to con- 

 centrate the voice npon a narrow space at the 

 middle of the plate ; and for Ms purpose a 

 movable wooden mouth-piece, a a, is used, 

 with an opening at the bottom about the size 

 of a dime. This mouth-piece should fit neatly, 

 and reach to within about one-eighth of an 

 inch of the diaphragm. 



Fig. 5 represents a section of Bell's tele- 



Fio. 5. 



phone. E E is the diaphragm, F the tube, B 

 the silk-covered wire wound upon the spool, 

 extending, C C, to the binding-screws D D, 

 where the two ends are connected with the 

 line-wires. The magnet A has its distance 

 from the diaphragm adjusted by the screw at 

 the opposite end. Fig. 6 represents the form 

 and aspect of the instrument as used. It is 



about five or six inches long and two and a 

 half inches broad at its widest part. In send- 

 ing a message, the instrument is held to the 

 mouth, and the words distinctly spoken in or- 

 dinary tones or even a whisper. Ihe instru- 

 ment is then held to the ear to receive the 

 answer. Instead of this, two telephones con- 

 nected may be used at each station, so that one 

 may be held to the 

 ear all the time, while 

 the other is used for 

 telephoning. 



The impression 

 produced by listen- 

 ing to a communica- 

 tion through this in- 

 strument has been 

 aptly described as fol- 

 lows : " The voice, 

 whether in speaking 

 or singing, has a 

 weird, curious sound 

 in the telephone. It 

 is in a measure ven- 

 triloqual in charac- 

 ter ; and, with the 

 telephone held an 

 inch or two from the 

 ear, it has the effect 

 as if some one were 

 singing far off in the 

 building, or the sound 

 were coming up from 

 a vaulted cellar or 

 through a massive stone-wall." The singing 

 or speaking is heard microscopically, as it 

 were, or rather microphonically, but wonder- 

 fully distinct and clear in character. 



The longest distance at which conversation 

 has been carried on, so far, through the tele- 

 phone, is about 250 miles. With a submarine 

 cable conversation has been carried on between 

 England and France across the English Chan- 

 nel. Conversation has also been held through 

 the bodies of sixteen persons standing 

 hand-in-hand. 



The telephone has been regarded as a 

 toy, or a curiosity to be played with ; but, 

 while it is undoubtedly extremely inter- 

 esting as a novelty, it is very much more 

 than this ; it is, scientifically and practi- 

 cally, a great success. There are, un- 

 doubtedly, difficulties in its use, but, con- 

 sidering that ft is a contrivance but of 

 yesterday, the wonder is that it is so per- 

 fect. The telegraph was much longer re- 

 garded as an impracticable invention, and 

 it is impossible to say how soon the tele- 

 phone may not take rank among the necessi- 

 ties of common life. 



TENNESSEE. The subject which most 

 largely occupied the attention of the public 

 authorities and the people of the State of Ten- 

 nessee during the year was that of a readjust- 

 ment of the State debt on a basis that would 

 make its requirements press less heavily upon 



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