FREE BOOKS

Author's List




PREV.   NEXT  
|<   141   142   143   144   145   146   147   148   149   150   151   152   153   154   155   156   157   158   159   160   161   162   163   164   165  
166   167   168   169   170   171   172   173   174   175   176   177   178   179   180   181   182   183   184   185   186   187   188   189   190   >>   >|  
diverting experience while it lasted. The excitement over the phonograph was maintained for many months, until a large proportion of the inhabitants of the country had seen it; and then the show receipts declined and dwindled away. Many of the old operators, taken on out of good-nature, were poor exhibitors and worse accountants, and at last they and the machines with which they had been intrusted faded from sight. But in the mean time Edison had learned many lessons as to this practical side of development that were not forgotten when the renascence of the phonograph began a few years later, leading up to the present enormous and steady demand for both machines and records. It deserves to be pointed out that the phonograph has changed little in the intervening years from the first crude instruments of 1877-78. It has simply been refined and made more perfect in a mechanical sense. Edison was immensely impressed with its possibilities, and greatly inclined to work upon it, but the coming of the electric light compelled him to throw all his energies for a time into the vast new field awaiting conquest. The original phonograph, as briefly noted above, was rotated by hand, and the cylinder was fed slowly longitudinally by means of a nut engaging a screw thread on the cylinder shaft. Wrapped around the cylinder was a sheet of tinfoil, with which engaged a small chisel-like recording needle, connected adhesively with the centre of an iron diaphragm. Obviously, as the cylinder was turned, the needle followed a spiral path whose pitch depended upon that of the feed screw. Along this path a thread was cut in the cylinder so as to permit the needle to indent the foil readily as the diaphragm vibrated. By rotating the cylinder and by causing the diaphragm to vibrate under the effect of vocal or musical sounds, the needle-like point would form a series of indentations in the foil corresponding to and characteristic of the sound-waves. By now engaging the point with the beginning of the grooved record so formed, and by again rotating the cylinder, the undulations of the record would cause the needle and its attached diaphragm to vibrate so as to effect the reproduction. Such an apparatus was necessarily undeveloped, and was interesting only from a scientific point of view. It had many mechanical defects which prevented its use as a practical apparatus. Since the cylinder was rotated by hand, the speed at which the record was forme
PREV.   NEXT  
|<   141   142   143   144   145   146   147   148   149   150   151   152   153   154   155   156   157   158   159   160   161   162   163   164   165  
166   167   168   169   170   171   172   173   174   175   176   177   178   179   180   181   182   183   184   185   186   187   188   189   190   >>   >|  



Top keywords:

cylinder

 

needle

 
diaphragm
 

phonograph

 

record

 

practical

 

Edison

 

rotating

 

effect

 

engaging


rotated

 

thread

 

mechanical

 

vibrate

 

apparatus

 

machines

 
engaged
 

necessarily

 

reproduction

 

centre


tinfoil

 

undeveloped

 

chisel

 

connected

 
adhesively
 

recording

 

prevented

 
original
 

briefly

 
slowly

longitudinally
 
Obviously
 

interesting

 

scientific

 

Wrapped

 

spiral

 

conquest

 
causing
 
defects
 

characteristic


indentations

 
series
 
sounds
 

musical

 

beginning

 

vibrated

 
depended
 

undulations

 

attached

 

formed