190 



NATURE 



[April 15, 1909 



starting, the resonator of both gramophones was | gramophone operators, say, of the sounds of an 

 removed, and the circular openings at the base of ' orchestra, air currents carried the vibrations against 

 each taper arm were connected by a wide tin tube, the diaphram of the recording instrument with suffi- 

 When the first gramophone acted the sound waves ' cient intensity to enable the recording needle to 

 passed, not out by the resonator, as usual, but cut its way into the soft matrix employed; but the 

 along the transverse tin tube to the other gramo- energy of tones coming from the sound-box of the 

 phone, the sound disk of which then vibrated and I reproducing gramophone (that is, the gramophone 

 wrote the tracings on the blackened glass plate. This working on the disk)' was, of course, very much 

 "lethod, apparently so simple, gave rise to great ! diminished; still, sounds were heard (the drum-head 



was moved), although no 

 movements of the disk of the 

 second gramophone could, by 

 the above method, be re- 

 corded. The amplitude of 

 the movements of the drum- 

 head must be inconceivably 

 small, and yet they are suffi- 

 cient to transmit pressures 

 to the nerve terminations in 

 the cochlea. 



These experiments were 

 made at home and without 

 the appliances of a laboratory, 

 and as, owing to circum- 

 stances, I cannot continue 

 them, I will be glad if the 

 method or methods above 

 described are taken up by a 

 younger worker. The sound 

 waves may also be seen by 

 the ingenious method of re- 

 flecting a beam of light 

 from a small mirror at- 

 tached to the diaphragm on 

 to a revolving Wheatstone 

 mirror. This method was 

 invented by Mr. Bowron. 

 Several years ago Dr. James 

 Erskine Murray showed me an arrangement of his 

 own of a similar kind. 



(4) The gramophone is an excellent phonauto- 

 graph. Take two gramophones ; one to draw the 

 needle over the smoked glass plate on a second 

 gramophone ; remove the resonator of the second 

 gramophone ; suspend the sounding box of the second 

 gramophone until the needle barely touches the 

 smoked glass plate; and then, through a wide tin 



) singing La Cahutn 



trouble owing to the sound-box of the second gramo- 

 phone being so heavy as to damp or obliterate many 

 of the vibrations transmitted from the first gramo- 

 phone. I substituted for the sound-box of the second 

 gramophone (i) one of Path^'s simple reproducers, 

 having, by a cork, a needle attached to the centre 

 of the disk ; (2) a very delicate tambour made by 

 -\lbrecht, of Tubingen, used in Heurthle's ingenious 

 arrangement for recording the sounds of the human 

 heart; (3) one of Brodie's 

 tambours, made by C. F. 

 Palmer; and (4) a capsule, made 

 by Joos, of Frankfort, for 

 Marbe's method of recording the 

 vibrations of Konig's flames. 

 The first gave the best results, 

 but was not quite satisfactory. 

 Nos. 2, 3 and 4 were of no 

 service, as they were too mobile, 

 and too susceptible of vibrations 

 due to inertia. The same objection 

 applied to the needle in No. i. 

 ."Mter a great deal of trouble, 

 however, I found the ordinary 

 sound-box of the gramophone 



most effective after suspending it •'"^ 3.— Record of vibrat 

 so as to remove weight, and so 

 as to allow the. needle to touch 



the smoked glass plate with a minimum of friction. 

 In these experiments one had a striking illus- 

 tration of the delicacy of the movements of the 

 drum-head of the ear. The more delicate tones, or, 

 rather, the weaker tones of a fine voice, on which 

 expression so much depends, were not recorded by 

 any of my mechanical appliances, and only loud, 

 strong, rich tones (like those of a powerful orchestra) 

 left their traces. When the record was made by the 



NO. 2059, VOL. 80] 



ns of human 1 

 lograph. ]i. 



1 the experiment of using the gramopho 

 : with magnifying glass. 



tube, having a diameter the same as that of the open- 

 ing at the end of the taper arm of the second gramo- 

 phone, speak or sing into the second gramophone. 

 Thus the vibrations are recorded, while the speed of 

 the smoked glass plate is known. Long ago I traced 

 vowel curves and other sounds (using a phonograph 

 recorder) on a vertical smoked glass plate moving 



It of the gramophone, see an interesting paper by Mr. 

 read before the Royal Society of Arts, May 6, 1908. 



