59S 



KA TURE 



[October 17. 189; 



is diflficult u' i" ii ulicther the mark made for each 

 additional note is the same Icnyth, for when three notes 

 are struck they may not each be struck witli the same 

 force. In the second case (Fig. 2 one note is struck, 

 held down and another struck, and so on, the previous 

 notes always being kept down. The effect ])roduced is 



achieved. When \ery quick passages are being played, 

 the strong wave of air shakes the drum so forciblv, that 



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"n .jj ILf 



I c i <. f 



L^Js^M " " 



Fig. 2. — EflTecls produced la, in striking one note, and 

 /•, f, (/, r, A in striking chords of two up to si-v 

 notes : in the second case, a', fi', c', if, e', in play- 

 ing five successive notes, and keeping them down. 



Fi<;. I. —Illustration of the apparatus. 



curiously like a flight of stairs, but the height of each 

 stair is not absolutely equal. This proves that the ap- 

 paratus is sufficiently sensitive to show, b\' the height of 

 the lines, the intensity with which a note is struck. 



With regard to ///«<•, it is reproduced with the utmost 

 precision, and it i- in order to guarantee accuracy that 



Fk;. ■?.— a represents effect without the insertion 

 the diaphr.iKin. li the effect with tlie diaphr.igni. 



the pen ceases to act properly. Much trouble has been 

 taken to devise ri u.iv of lessening the force of the wa\e : 



■M.■^f^^/JA•M^M^MMr^fJM^. A\^A^^^/U^M^A^/\«A«^f/u^A^AA^AA^AAA»^AA«AMA 



Fti;. 4.— Shake executed with ltr,l and second finger. 



the luljc i.-. connected tn the drum at both ends, otherwise 

 the notes situated near the end which was not connected, 

 would be further removed from the drum than the others, 

 and this would cause a delay in their being registered. 



The graphical form ought theoretically to be an imita- 

 tion of the movement played, but this result is not often 



KO. 1355, VOL. 52] 



amongst other materials, cotton has been inserted inln 

 the tube, but these experimenls were not eiuircly suc- 

 cessful. It has been foun<l that<pl.icing a diaphragm with 

 a small hole in tlie tube, lessens the force of the wave of 

 air very considerably, and to a certain extent prevents 

 the drum Mbrating too strongly. 



