1873 J 



151 



[Chase. 



II. "\Yaye-Lenc4ths of Light and Sound. 



Musical N/otes. Length. 



A 3077 



B 2735 



C 2564 



D 2279 



E 2051 



F 1923 



G 1709 



A 1538 



Mean, Arith. 2234 



" Geo. 2180 



By a singular fortuitous coincidence, the same names 

 have been given to the principal nodes in the luminous 

 octave, and to the corresponding notes of the Diatonic 

 Scale. Althotigh the differences between the analogous 

 wave-lengths are too great to be strictly harmonized with 

 any known musical scale there can be no hesitation in any 

 single instance, as to the proper notes for comparison. 

 The tendency to minor intervals in the spectrum, the closeness of the 

 agreement at F, which has been called "the key-note of nature." and 

 the equality of the means, may, possiblj, have something more than a 

 merely curious significance. Analogies of this description, based on the 

 lines which are most prominent, are much more satisfactory than those 

 between the more minute and more numerous microscopic lines. 



All musical scales being more or less artificial, one might, perhaps, be 

 constructed, which should agree more closely with the luminous gamut 

 than any hitherto proposed. Table III. exhibits some interesting features 

 of reciprocal resemblances to Poole's "Double Diatonic Scale."' The 

 left haud column gives the number of vibrations of the successive musical 

 notes ; the middle column, the wave-lengths of the Fraunhofer lines ; 

 the right hand column, a set of wave-lengths in which the intervals are 

 the same as Poole's but differently arranged and not fitted for harmony. 



III. Luminous and Double Diatonic Scales. 



In six out of eight notes, the agreement with Poole's Scale is remark- 

 ably close. The differences from the False Scale are all slight, in no case 



