86 
ROBERT JAMES KELLOGG 
amplitude that they are wholly illegible on any scale of enlarge- 
ment. In other words, the difficulty rests for both instruments 
in the fact that the record is not made for visible but only for 
audible purposes. The remedy obviously lies in constructing 
phonograph and gramophone records for the express purpose of 
microscopic enlargement without regard to their fitness for 
audible reproduction (though a synchronous audible record 
could also be made for comparison if desired). 
In the case of the phonograph, a micro-legible record could be 
made by using a wedge-shaped cutting sapphire (that is, one 
with two straight cutting edges meeting in a' point) , thus making 
the depth and width of the groove proportional and the edges 
true sinusoids of the sound vibrations recorded, and as such 
capable of direct microscopic enlargement and photographic 
reproduction and interpretation. Whether it could be made 
more easily legible and photographable by a surface coloring of 
the wax, could be determined by trial. 
In the case of the gramophone, a micro-legible record could 
easily be made by sufficiently reducing the speed of the record- 
ing disk, thus foreshortening the vibrational curves to legible 
sinusoids. Such a record ought to be easily magnifiable suffi- 
ciently to show the minutest phases of vowel and consonant 
vibrations. 
The unsatisfactory results hitherto attending microscopic 
enlargement of *the sound groove led to various efforts at indirect 
enlargement, either by physical levers (as by Scripture,^ Muen- 
zinger^® and others), or by physical and light-levers combined 
(as by Hermann,^^ Rosset^^ ^nd others). 
Scripture apparently carried the simple lever apparatus to 
the limit of its possibilities. He himself adjudges it inadequate 
and believes that ^Hhe future of the method lies in the develop- 
® Elements of Experimental Phonetics, ch. IV, and Study of speech curves, 
Washington, 1906, ch. II. 
Bull, of Univ. of Texas, no. 24, April, 1915. 
See Elements of Experimental Phonetics, p. 38 ff, with the references there 
given. 
Recherches experimentales pour I’inscription de la voix parlee. Paris, 1911. 
