OP ARTS AND SCIENCES. 273 



former, we have noted only those sounds which seemed most promi- 

 nent in the different series. 



(1) The vowel 6 was spoken into the speaking-tube of the phono- 

 graph when the cylinder was rotated at the lowest speed at which 

 it was possible to drive it with the governor used, — about one 

 half-revolution per second. The vowel was then reproduced with a 

 gradually increasing speed of the cylinder up to the highest possi- 

 ble speed, — about three and one half revolutions per second. The 

 experiment was repeated several times, and with different observ- 

 vers. The sounds heard as represented were 



6" o ou u a. 



(2) The vowel o was spoken into the mouthpiece at a speed of 

 about one revolution per second. On reproducing it at lower rates 

 down to about one half-revolution per second, the vowel sound was 

 still heard as o, but becoming more and more guttural, until at the 

 lowest speed it sounded like a deep gurgle. 



(3) The vowel o spoken with a moderately low speed of the 

 cylinder, and reproduced with gradually increased speeds from 

 the lowest possible to the highest, gave the following sounds : — 



6 o o ou a a. 



(4) The vowel o was spoken into the instrument at the highest 

 attainable speed, and repeated a number of times, the speed of the 

 cylinder meanwhile being lowered gradually, so that the vowel in 

 question was impressed upon the cylinder at a variety of speeds, 

 from the highest to the lowest. It was then reproduced with grad- 

 ually increasing speed of the cylinder, beginning with the lowest 

 possible. This procedure was well adapted to give a large num- 

 ber of vowel sounds in succession. The reproduced vowels noted 

 were 



6 o o on a a i. 



(5) The vowel o spoken at the lowest possible rate was repro- 

 duced at gradually increasing speeds. The sounds heard were 



5 a a e i. 



(6) The vowel o spoken at a rate of about one revolution per 

 second was reproduced at a lower speed as o and at the lowest 

 attainable speed as a very deep guttural 6. 



(7) The vowel e spoken with a cylinder speed of about one revo- 

 vol. xxvn. (n. s. xix.) 18 



