TRACING GRAMOPHONE AND PHONOGRAPH RECORDS. 35 



can not be detected by the ear. How a single vibrating string can pro- 

 duce such beats is a problem for investigation. Lack of homogeneity in 

 the string may be the cause. 



The curves in figure 41 are from the "Graham record"; they were made 

 by a single lever and have a magnification of 124 and a time equation 

 of 1mm. = 0.00022s. The figure reproduces apiece of a mount three times 

 as wide ; each hne therefore shows the last third of the line on the mount. 

 Line 139 gives the curve of [i] in "before"; hues 140-143 give pieces out 

 of beginning, middle, and end of [o] in the same word. Lines 144 and 145 

 give portions of the beginning and end of the vowel [a] in " such." Lines 

 146 and 147 give waves from [9] belonging to the article "a." Line 148 

 is from [ai] of " highly." 



The first two specimens in plate vii are from a record by S. Weir Mit- 

 chell. The former gives one-fifth of the exclamation "oh" spoken sorrow- 

 fully. We observe the gradual change in the form of the waves throughout 

 the " oh," indicating that the sound of the vowel changed slowly. The 

 second specimen gives the last half of [e] (not [s] ) followed by [Ji] from 

 the word "America." We note that the strong vibrations for [e] become 

 weaker as the sound ghdes into the "untrilled r." This "r" includes 

 at least two wave-groups of small amplitude; the weakness of the vibra- 

 tions indicates that it is a consonant "r" and not a vowel "r." The 

 vibrations gradually increase in strength as the [i] is produced ; this is a 

 very short sound fading away rather abruptly before the [k] which fol- 

 lows the last wave in the hne. The third specimen on the plate is from 

 a Chinese vowel; the type of the wave in the first portion of the record 

 is far more constant than in American vowels, but the inevitable gradual 

 change appears in the latter part. The next curve on the plate is a small 

 portion of a trill by an Italian voice (Mme. Chalia) on a high note. We 

 notice at once that the amplitude rises and falls, that is, that the intensity 

 changes. This is the characteristic of a tremolo, not of a trill. These 

 variations of intensity show indications of periodicity in time, but they 

 are very irregular in amount and duration ; the first hne of the piece selected 

 starts with a weak portion, a second one occurs in the middle of the same 

 line, and a third at the end of it; the second one is weaker than the first 

 and the third is still weaker. The third region of weakening is longer 

 than the others, extending into the second hne. The fourth weakening, 

 which occurs in the second line, is most marked of all. A faint weakening 

 occurs toward the end of the second line and irregular weakenings occur 

 in the third hne. The pitch of the tone— length of the waves— varies 

 somewhat irregularly from vibration to vibration, but does not rise and 

 fall as required in a correct trill, which is Supposed to be an alternation 



