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apparent anomaly of the tones produced, especially where 

 the tones differ by about half a tone from that of the true 

 interval of the proper harmonic tones. 



It is well known that bells, in addition to the primary 

 vibrations, which are similar to the lower tones produced 

 from plates, give harmonic vibrations at the same time. 

 We may, therefore, perceive the reason of the great 

 difference in the tone of large bells ; all have harmonic 

 tones in addition to the primary tones, but from differences 

 in the disposition of the metal of the bell, there may be 

 produced harmonic tones discordant to the primary tones. 



The appearance of progressive motion may be produced 

 by bodies moving only in direction transverse to that of the 

 apparent progressive motion. It is known that the motion 

 of waves on the surface of water is of this nature, for on 

 observing a small body, as a piece of cork, on the surface 

 of the sea, the cork is seen to move up and down, but does 

 not partake of the apparently rapid onward progress of the 

 wave. This motion we will, therefore, term wave motion. 



But in observing the property which small elastic bodies 

 possess of communicating their motions one to another, 

 and yet appearing themselves to be at rest, it appears 

 that we discover a path which, being carefully pursued, 

 may lead us to right apprehension of many of the phe- 

 nomena of small but rapid motions ; probably of those 

 mysterious agents which are now comprehended under the 

 term Actinism, a term suggested by Sir John Herschell, 

 and agreed by the Physical and Chemical Sections of the 

 recent meeting of the British Association at York, to be 

 for the future the general designation of radiants, whether 

 light, heat, or chemical rays. 



By means of a few marbles suspended by threads, it will 

 be observed, that when one of the marbles is made to 

 impinge against the others, the motion is communicated 



