No. 53542. 



Frequency Curves. Tuning Fork Apparatus. 



453 



53530. 1:6. 



53 542 A. 1:10. 



53541. 1:6. 



53542B. 1 : 10. 



large vibrations. Tney are provided with steel mirrors and adjusted at 20 C. Both forks nave electro- 

 magnetic drive. 



By means of two sliding weights one fork can be put out of tune for producing tremors. 



By aid of the Projection Lantern and a Lens the curves can be very beautifully projected on to 



a screen. 



* 53,542. - - i d e in, with arrangement, in addition, to enable compound parallel vibrations 

 to be objectively demonstrated, with two diaphragms on one fork and a string support 

 on the other, one Stand, Fig. A, and a Lath on which a catgut cord is to be stretched, 

 Figure B 



The five following very beautiful experiments can be carried out with the apparatus: 



(1) Subjective observation of the Lissajous Curves (M. P. I, Fig. 688 [712]); 



(2) Objective demonstration of the Lissajous Curves on the sc.?en by means of the Projection Lantern; 



(3) Objective demonstration of the sine curves produced by compound parallel vibrations (M. P. I, Fig 808 

 [832]); 



(4) Observation of the Vibrations of a Fork by Mach's Stroboscopic Method (M. P. I, p. 668 [738]); 



(5) Observation of the vibrations of string by the same method (M. P. I, p. 670 [740]). 



Complete description is appended to the apparatus. 



Stroboscopic Disc driven by Electric Motor, for observing the condition of vibration - - see 



under No. 53,304, p. 432 



s. d. 



15. 0. 



12. 0. 



* Can be used with the Projection Apparatus. 



Cl. 1137. 1139, 

 1138, 1110. 





