Q. Why can we hear distant clocks most distinctly in clear cold weather?
A. Because the air is most uniform then: there are not two currents of air (one up and one down) to interrupt the sound-waves.
Q. Why can persons hear the voices of men in conversation for a mile distant, near the poles, in winter time?
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 conversation, 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 falling 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.