Jan. 20, 1888.] 



SCIENTIFIC NEWS. 



51 



THE EDISON PHONOGRAPH. 



THE new phonograph, which forms the subject of 

 our illustration, is of about the size of an 

 ordinary sewing machine. In its construction it is 

 something like a small engine lathe ; the main spindle is 

 threaded between its bearings, and is prolonged at one 

 end to receive the hardened wax cylinder upon which 



The device for reproducing the sound consists of 

 a cell containing a delicate diaphragm of gold-beater's 

 skin, to the centre of which is secured a stud con- 

 nected with a small curved steel wire, one end of 

 which is attached to the diaphragm cell. The spindle ot 

 the phonograph is rotated regularly by an electric motor 

 in the base of the machine, which is driven by a current 

 from one or two cells of a battery. The motor is pro- 



<£he sound record is made. Behind the spindle and the 

 ■cylinder is a rod upon which is arranged a slide, having 

 .■at one end an arm adapted to engage the screw of the 

 .•spindle, and at the opposite end an arm carrying a 

 (pivoted head, provided with two diaphragms, whose 

 .position may be instantly interchanged when desirable. 

 One of these diaphragms is turned into the position of 

 -use when it is desired to talk to the phonograph, and 

 "^vhen the speech is to be reproduced, the other diaphragm 

 ttakes its place. 



vided with a sensitive governor which causes it to main- 

 tain a very uniform speed. Motion is transmitted from 

 the motor to the spindle by bevel friction wheels. The 

 arm which carries the diaphragms is provided with a 

 turning tool lor smoothing the wax cylinder preparatory 

 to receiving the sound record. The first operation in 

 the use of the machine is to bring the turning tool into 

 action and cause it to traverse the cylinder. The turning 

 tool is then thrown out, the carriage bearing the dia- 

 phragms is returned to the position of starting, the 



