MUSICAL TONES. 65 



feet, I might have seen the act a thousand years 

 after it was committed." It would seem that sun- 

 beams are recording angels. 



VARIED RAPIDITY OF VIBRATIONS OF THE ELECTRIC AND 

 ATMOSPHERIC ETHERS PRODUCE PRISMATIC COLORS 

 AND MUSICAL TONES. 



The principal difference between the transmis- 

 sion of impulses by the electric and atmospheric 

 ethers is due to the extreme elasticity and light- 

 ness of the former, as manifest in the transmis- 

 sion of a flash of lightning with the velocity of 

 light (one hundred and ninety thousand miles per 

 second), while the sound of thunder traverses the 

 air with the velocity of only eleven hundred and 

 fifty feet per second. 



When vibrations of the air impinge against the 

 tympanum of the ear less often than twenty-eight 

 pulsations in a second, each one is distinctly heard; 

 but when more rapidly repeated, a fresh impulse 

 is received before the tympanum comes to a state 

 of rest, thus producing a continuous humming 

 sound, until one hundred and twenty-eight vibra- 

 tions per second are reached. Then the regular 

 musical tone of the bass note, c, is heard. 



By increasing the number of vibrations of the 

 air from one hundred and twenty-eight to one 

 hundred and forty-four per second, the next higher 

 musical tone of the gamut is produced ; and so 

 on successively, each higher note up to one hun- 



5 



