Experimenting with the Phonoscribe 



This 7nachine is sometimes re- 

 ferred lo as a "phonoscribe." It is 

 designed to lake dictation, writing 

 words down on paper in natural 

 characters as fast as spoken. It is 

 of interest here us a forerunner of 

 the voice-operated typewriter. The 

 man at the right is pronouncing tlie 

 word "boat" as an example. The 

 being silent, produces no effect on 



in boat, 

 the machine, 

 since it must necessarily spell words phonetically, 

 or as they sound. The "bot" sound vibrations 

 proceed into the transmitter and affect an electric 

 circuit in which are 12 'inbrating-mirror mechan- 

 isms. Detail of these is given in the figure below. 

 Each mechanism is tuned by the small coils back 

 of it so that it will only respond to vibrations, or 

 cycles, of a certain magnitude. See page 70 for 

 further description. 



The black rectangles beneath the word "(Boat)" 

 at right make clearer the workings of the selenium 

 cell shown in the picture above. They may be 



considered a series of instantaneous views of the 

 selenium cell while the light beams are varying in 

 length over its surface. The white strips in the 

 center of each view show how much the light 

 beams happened lo be vibrating at each particular 

 instant. The white curves connecting the bottoms 

 and lops of these strips of course have no real 

 existence but were drawn in lo show how the 

 light-beam lengths follow the original shape of the 

 word "boat" as sketched in, in front of the man's 

 face. \ole also how the curve traced by the 

 solenoid and pen varied directly with the length of 

 these light-beams, tracing the identical curve. 



TUNED MAGNETIC STRIP 



MIRROi 



TUNED MAGNETIC STRIP 



REFLECTED LIGHT BEAM 



SELENIUM CELL 



CRANK-PIN O 004 EROM 

 CENTER LINE OF SHAFT 



BLANK SPACE 

 ■NS \6HADE 



TukOiTEN OR OTHER POINT USHT 

 DIRECT LIGHT BEAM 

 CRANK-PIN 

 GERMAN SILVER CONNECTING ROD 



Detail of mirror-muiinf^ mechanism. ."Similar 

 lo a telephone receiver in general construction, the 

 tuned magitetic strip taking the place of the usual 

 diaphragm. Attached to the strip is a short lever 

 working a liny crank-shaft on which a little mirror 



is mounted. \'ibralions Irom thr \lrtp rotate the 

 crank slightly causing the mirror lo move through 

 a small arc and throw its beam of light up and 

 down OH a selenium cell in the manner shown in 

 the illii^trnlion at the top of the page. 



t)7 



