THE UNIVERSAL FAMILY PAPER FOR INTER-COMMUNICATIONS ON 



,n 



Conducted by WILLIAM KIDD, of Hammersmith,— 



Author of the Familiar and Popular Ess at s on "Natural History;" "British Song 

 Birds; " "Birds of Passage;" "Instinct and Reason;" "The Aviary," &c. 



"the OBJECT of our work rs to make men WISER, without obliging them to turn over folios and 



QUARTOS.— TO FURNISH MATTER FOR THINKING AS WELL AS READING."— EVELYN. 



No. 36.— 1852. 



SATURDAY, SEPTEMBER 4. 



Price M. 



Or, in Monthly Parts, Price Is. Id. 



THE NATUHE OF SOUND. 



There are so very many subjects of 

 intense interest, yet of which so very 

 little is understood, albeit we are made 

 sensible of their effects, if not their causes, 

 daily — that we purpose bringing them, one 

 by one, under the public eye. No doubt, 

 there are many " children of a larger 

 growth," to whom, as well as to our younger 

 readers, these matters may not be perfectly 

 well-known. 



We will to-day treat of the Philosophy of 

 Hearing. The human ear and its passages 

 are indeed a most wonderful study. 



The intimations of the external world 

 which we receive through the ear, are the 

 result of certain concussions that take place 

 among the objects around us. When 

 bodies are brought into sudden contact, or 

 a single body is made to vibrate or 

 expand suddenly, it must displace a quan- 

 tity of the surrounding air. The air which 

 is thus displaced, in its turn displaces 

 that portion of air which is next to it, 

 or beyond it ; on every side, above and 

 below, before and behind, on the right 

 and on the left. This displaced portion of 

 air displaces again what is beyond it, and so 

 on, in a manner similar to the circles of 

 water which arise from throwing a stone into 

 a pond. In the case of sound, however, 

 the waves are not in superficial circles, but 

 in spheres, like the coats of an onion. The 

 air besides is elastic, or has the quality of 

 springing back to its first position like 

 India rubber when stretched out and let 

 go. Therefore the waves of sound are not 

 regularly progressive like those of water ; 

 but vibrate or tremble forwards and back- 

 wards, as a musical string is seen to do when 

 it is struck. The first wave accordingly, 

 when it strikes on the air around it, drives 

 this air forwards, while it is itself driven 

 backwards. 



This shows that the motion of sound is 

 also very different from that of wind, and is 



scarcely, if at all, perceptible to sight or 

 touch ; for it is well known that sounds 

 which would shatter windows to pieces will 

 not move a feather, nor the flame of a 

 candle — so different is the motion from wind. 

 Though, however, sound is not usually felt 

 by touch, there are instances in which it 

 appears to have been thus perceptible. 



Kersting, who lost both his sight and 

 hearing after manhood, had his sense of 

 touch so wonderfully improved, that he 

 could read a book of large print by passing 

 his fingers along the lines. He was also a 

 practical florist. But the most wonderful 

 faculty which he possessed, was that of 

 distinguishing sounds by the touch, being 

 able to comprehend the greater part of a 

 conversation when the mouth of the speaker 

 was applied to his hand. The letter R, 

 however, grated so much on his feelings, 

 that his friends took care to pronounce it as 

 seldom as possible. This feeling is distinct 

 from the sympathetic thrilling occasioned by 

 certain sounds, and felt all over the body. 

 Lackington, the celebrated bookseller, in 

 his Memoirs, mentions a lady who, though 

 deaf, took great delight in music, which she 

 said she felt at her breast, and in the soles 

 of her feet. Of course we do not rest much 

 on this instance, though it is not improba- 

 ble. 



Sound is in this manner propagated, or 

 travels in all directions from the place 

 where it is produced. The quickness with 

 which sound travels is much inferior to the 

 quickness of light, which goes 95,000,000 

 miles — that is, it comes from the sun to the 

 earth — in eight minutes and a half, while 

 sound only goes 1,142 feet in a second. By 

 knowing this, we can make near estimates 

 of distances otherwise inaccessible. A 

 thunder cloud, for example, will be between 

 six and seven miles distant, if half a minute 

 elapses from the time we see the lightning 

 to the time we hear the thunder. The dis- 

 tance of a ship at sea is calculated in the 

 same way, by attending to the difference of 



Vol. II. 



