414 DISTANT SOUNDS. 



A. Because the air is very cold and 

 very clear; in consequence of which, 

 there are not two currents of air (one up 

 and one down) to interrupt the sound- 

 waves. 



Captain Ross heard the voices of his men in con- 

 versation, a mile and a half from the spot where they 

 stood. 



Q. Why are not SOUNDS (such as distant 

 church bells ) heard so distinctly on a HOT DAY as 

 in FROSTY weather ? 



A. Because there are two currents of 

 air ; the current of hot air ascending from 

 the earth, and the current of colder air 

 fatting towards the earth ; and these two 

 currents break up the sound-waves. 



Q. Why can we not hear SOUNDS (such as 

 distant clocks) so distinctly in a thick MIST or HAZE, 

 as in a CLEAR night ? 



A. Because the mist diminishes the 

 velocity of the sound-waves, and (by 

 overburdening them with vapour) limits 

 their length. 



Q. Why do we hear SOUNDS better by NIGHT 

 than by DAY ? 



A. 1st Night air is more uniform, 

 because the ascending currents of air 



