THE GRAMOPHONE EEDDIE. 



231 



That concludes my paper. I have an instrument here which will 

 enable you to see the curve of the actual sound waves of a record 

 being produced by means of a spot of light reflected from a small 



mirror attached to a gramophone diaphragm on to a revolving mirror 

 and thence on to a screen. The apparatus is one invented by Mr. G. 

 Bowron. 



88292— SM 1908 16 



