166 THE SEASON WHY. 



" And I will cause the noise of thy songs to cease ; and the sound of thy harps 

 shall no more be heard." EZEKIEL xxvi. 



732. Is air a good conductor of sound ? 



Air is a good conductor, but water is a letter conductor than 

 air ; wood, metals, the earth, &c., are also good conductors. 



733. Why can we Jiear sounds at a greater distance on 

 water than on land ? 



For various reasons : because the smooth surface of water is a 

 good conductor; because there are fewer noises, or counter 

 vibrations, to interfere with the transmission of sound ; and because 

 there are no elevated objects to impede the progress of the 

 vibrations. 



734. Why do sea-shells give a murmuring noise when held 

 to the ear ? 



Because what may be called expended, vibrations always exist in 

 air where various sounds are occurring. These tremblings of the 

 air are received upon the thin covering of the shell, and thus being 

 collected into a focus, are transmitted to the ear, 



735. Why can people in the arctic regions converse ivhen 

 more than a mile apart ? 



Because there the air, being cold and dense, is a very good 

 conductor; and tae smooth swface of the ice also favours the 

 transmission of sound. 



736. Why do savages lay their heads upon the earth to hear 

 the sounds of wild leasts, fyc. ? 



Because the earth is a good conductor of sound. For this reason, 

 also, persons working under ground in mines, can hear each other 

 digging at considerable distances. 



737. Why can church clocks be heard striking much more 

 clearly at some times than at others ? 



Because the density of dry air improves the sound-conducting 

 power of the atmosphere. The transmission of sounds is also 

 assisted by the direction of the winds. 



738. Why may the scratching of a pin at one extremity of 



