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A NEW PHON AUTOGRAPH. 
stage further ; for in this instrument the metallic disc not only 
took up the vibrations both of vowels and of consonants, hut 
recorded them by indenting their form into tinfoil, and reproduced 
them again when forced mechanically to follow the ups and 
downs of the recorded tracing. 
Our knowledge of the exact nature of the voiy^Z-sounds, and 
of the characteristic form of their vibrations, is now very 
complete, thanks to the independent researches of Helmholtz, 
Bonders, and Konig, and to the study of their traces with the 
Phonautograph and Phonograph. 
Our knowledge, on the other hand, of the exact nature of the 
vibrations of the consonants is extremely imperfect. The Phon- 
autograph did not record consonantal tracings ; the Logograph 
merely recorded mechanical displacements due to varying air 
pressures. 
I therefore have proposed a new Phonautograph for the 
purpose of investigating the quality of the consonantal sounds. 
Its receiver is precisely like the receiver of my Phonograph — ^a 
disc of ferrotype iron, behind a mouthpiece like that of the 
Telephone. A small system of levers, working on spring joints, 
carries the motions of the disc to a needle-point which rests 
lightly above a horizontal bed, along which smoked pieces of 
ordinary window-glass are drawn by a clockwork arrangement. 
I believe it will be of great advantage thus to substitute 
tracings on a flat surface for tracings on a cylindrical one, as 
they can more easily be taken away from the instrument for 
purposes of observation, and for observation in the microscope. 
I also invite attention to the clockwork arrangement, and the 
means by which a perfect maintaining motion is obtained with 
a weight hanging upon an endless chain which passes over a 
winding pulley armed with a ratchet-click, as well as over the 
driving pulley. 
No connected experiments have yet been made with the 
