Show VOICE THROWN ONSCREEN ON ONSCREEN ONSCREEN SCREEN BY NEW PLAN An instrument known as the tho tono- tono scope projects tho the vibrations of ot the voice upon a a. screen on the tho principle of moving pictures in such a way that the singer er o oj or speaker can see sec the pitch of ot hit his voice the instant ho lie sings or speaks The instrument Is used especially espe cape dally daily n training singers and in makIng mak mak- ing InS scientific investigations on singing The singer standing at the tho side of ot a telephone apparatus sings In front of It or directly Into a 11 speaking tube and the vibrations of the tho voice cause a littIe lit little lit lit- tIe tle- flame Clam in a 3 a capsule at the center of tho the front of the apparatus to flicker so 80 that It actually goes oes down and rises with every vibration of ot tho voice In Ineide Inside In- In side elde of tho the case Is a n large drum containing containing con con- taming over holes arranged in rows rowe so as ac to represent a series which makes make s a complete octave If It for tor ex example ox- ox ample the tho singer er sounds middle C which makes vibrations per second the line lino on the drum which has hal holes will vIlI seem to stand still NUll and all nil the tho other rows are arc moving Tho The line lino which stan stands 18 still points to that number number num num- ber on the scale If he should sing a n I trifle sharp then 2 7 or oven even ovena I I a a. higher line stand still sun and if he should sing flat fIat a line Une of lower frequency frequency fre- fre I quency would stand still indicating j I Ithe the tho exact pitch The Instrument is de described do- do scribed with illustrations in the February February February ary Popular Mechanics Magazine |