602 



BELL SySTEM TECHNICAL JOURXAL 



the rotating drum. Tluis tin- time scale was accurately determined 

 for each record. 



Especial care was taken with the optical system to insure fine defi- 

 nition and strong illumination of the spot on the film and the films 

 were developed for maximum contrast. As a result, the records were 

 sufficiently clear to permit their reproduction by the line-engraving 



J4sea 



j55ec. 



.34 sec 



.353ec. 



--^ 



^/H/Vv^^-vs/^^^'"- — -^..^ 



I ig. 1 1 —Section of original record showing timing wave 



|H()( <^^. 1-^ach of the plates shown in this paper is made up of o\er- 

 lapping sections from the original record, each faithfully reprotiuccd, 

 and the whcjle arrangetl to gi\e liie complete record within the limits 

 of one page. A section of <>ni' ol ilu' origin, il records as takni is sluiwn 

 in the figure above. 



Ill 



("l..\SSIFlC.\TION OK Tllli RlXOKDS 



In selecting and classifying the vowel soimds for record, use has 

 been made, with slight alteration, of the phonetic arrangement adopted 

 by I'letcher (ref. S \\). This arrangement of the vowel sounds is 



