THE RESONANT RECORDER 



17 



holding the glass recording-plate, moves up and down the 

 top part of the upright. It is essential to have this slide so 

 accurately fitted that the plate-carrier may be able to drop 



cm 



Fig. 3. — Upper part of Resonant Recorder. (From a Photograph.) 



Thread from clock,' not shown, passes over pulley p, letting down 

 recording-plate ; s', screw for adjusting distance of writing-point 

 from plate; s, screw for vertical adjustment; t, tangent-screw 

 for exact adjustment of plane of movement of recorder, parallel to 

 writing-surface ; axis of writer supported perpendicularly at centre 

 of circular end of magnet ; c, coercer ; m, micrometer-screw for 

 adjustment of length of coercer; v, vibrating recorder ; G, smoked- 

 glass plate. 



smoothly and uniformly, without any jerking whatsoever. 

 I have sometimes attained the same end by mounting the 

 plate-carrier on wheels and letting it slide down vertical rails. 

 The plate-carrier is allowed to drop by the running down of 



