132 Mr, Tomlinsons Experiments and [Aug. 



73. The results of these observations on the three bells 

 of St. Paul's may be thus stated. 



Fundamental Tones. Secondary Tones, 



Large bell A D. F. sharp A 



1st Small bell . . . E G sharp B 

 2nd Small bell ... A C sharp E 



74. From these experiments and observations on bells, I 

 feel no hesitation in stating the fourth proposition of this 

 paper. 



That during the vibration of a hell, formed of the usual metal, 

 a series of secondary tones are elicited, which hear a 

 strict musical relation to the fundamental note. 

 In stating this proposition, I have purposely omitted 

 mention of those solitary notes mentioned at the latter 

 part of (68), being willing to make further experiments 

 and observations on this point, the only one perhaps that 

 bears any analogy to the discordant secondary notes of the 

 glass goblet. I desire also to state that although the subject 

 of this paper scarcely comes under Visible Vibration, still 

 I have retained the term, because I have found it con- 

 venient for the sake of reference to consider this paper as 

 part of the two preceding. In the subsequent papers the 

 term visihle will be found more applicable. 



75. I cannot better conclude this paper, than by giving 

 an account of some very singular phenomena noticed, within 

 the last week or two, by my friend Mr. George Dodd. 



Mention has been already made (61, note) of the production 

 of two tones by the percussion of an earthenware mug, &;c. As 

 it was thought probable, that friction on the edge had afforded 

 a similar result, and had been overlooked by me, Mr. Dodd 

 vibrated a common blue cylindrical cup, and found not only 

 that two notes, D and E, were produced separately, but that 

 they each alternated four times during one revolution of the 

 finger : that is, there were four points during the revolution 

 where D was produced, and four other points which pro- 

 duced E. These points were not exactly equi-distant, for 

 reasons before mentioned (12.), but the alternations were 

 very distinct. A jug with a lip was next tried, with the 

 same results, the lip offering no obstruction to the develope- 

 ment of the tones. On pouring water into these vessels the 

 notes produced were lower in the scale (54.), and what is 



