88 NATURAL HISTORY. 



the rift, it will make a fearful roaring at the window. 

 The cause is the same with the former ; for that all 

 concaves, that proceed from more narrow to more 

 broad, do amplify the sound at the coming out. 



141. Hawks bells, that have holes in the sides 

 give a greater ring, than if the pellet did strike upon 

 brass in the open air. The cause is the same with 

 the first instance of the trunk ; namely, for that the 

 sound inclosed with the sides of the bell cometh forth 

 at the holes unspent and more strong. 



142. In drums, the closeness round about, that 

 preserveth the sound from dispersing, maketh the 

 noise come forth at the drum-hole far more loud and 

 strong than if you should strike upon the like skin 

 extended in the open air. The cause is the same 

 with the two precedent. 



143. Sounds are better heard, and farther off, in 

 an evening or in the night, than at the noon or in 

 the day. The cause is, for that in the day, when 

 the air is more thin, no doubt, the sound pierceth 

 better ; but when the air is more thick, as in .the 

 night, the sound spendeth and spreadeth abroad 

 less : and so it is a degree of inclosure. As for the 

 night, it is true also that the general silence helpeth. 



144. There be two kinds of reflexions of sounds; 

 the one at distance, which is the echo ; wherein the, 

 original is heard distinctly, and the reflexion also dis 

 tinctly ; of which we shall speak hereafter : the 

 other in concurrence ; when the sound reflecting, the 

 reflexion being near at hand, returneth immediately 

 upon the original, and so iterateth it not, but ampli- 



