78 SIGHT AND HEARING. 



nature, and the other to learn from our fellow-men, 

 and yet the two work beautifully together for our in- 

 struction, and, as one may say, take counsel and strive 

 together to make us wise and happy. These are our 

 sight and our hearing, and so admirably are they 

 formed that they are not only more easily, and may 

 be more extensively educated than any of our other 

 senses, but we can heighten their powers by artificial 

 means. 



The speaking-trumpet augments the sound of him 

 who speaks, and the hearing-trumpet concentrates 

 and strengthens the sound to him who hears ; and 

 those who are acquainted with the observed laws of 

 sound can so manage matters as that a whisper can 

 pass silently over a crowd, and be heard distinctly 

 by a more distant person by whom it is intended to 

 be heard. Sound also may be doubled and redoubled 

 by reflection from surfaces ; and it is very possible 

 to hear one of those reflected sounds when the ori- 

 ginal sound is not heard. There is a very familiar 

 illustration of that. If you are in a house with 

 equal windows, equally open on all sides of it, and 

 if it thunders, or if ordnance fire, or the bell tolls, or 

 any other loud sound is produced, you are utterly 

 unable to tell on which side of the house the sounding 

 body is situated. If there are windows only on one 

 side of the apartment, you get a notion of the di- 

 rection of the sound ; but it is probable that notion 

 is a wrong one, because the room has four sides ; and 

 unless you have something else to guide your con- 

 clusion, you invariably suppose that the sound is upon 

 the side where the open windows are. 



The ear is a beautiful instrument, and the degree 

 of nicety to which it can be educated is quite aston- 

 ishing ; but still we are unable so to understand the 

 instruments or analyze the process of hearing as 

 to be able to say in what it consists ; and, as a direct 

 means of observing nature, pleasure rather than in- 

 formation is what it brings us. We know that sound 

 is produced by some sort of motion in the sounding 



