THE DRUM. 515 



The strange point in it is, that it represents a double head 

 carrying, after all negro fashions, a sort of vessel upon it. One 

 part of the head represents a human head (not that of a negro), 

 while the other merges gradually into an eagle's head and beak. 

 It is, in fact, a Grnostic gem, and would pass muster as such 

 if it had been engraved on chalcedony, cornelian, or other 

 semi-precious stones which are employed in the seal-engraver's 

 art. 



Upon this composite head is placed the Drum itself, which 

 is also cut out of the solid block, and which, after the fashion 

 of West African Drums, has a hole on one side. 



This remarkable instrument was given to me by an old 

 merchant captain, who brought it himself from West Africa, 

 and who, when I made his acquaintance, had actually painted 

 it all kinds of colours, planted it in his garden, and was using 

 the Drum as a flower-pot. Of course, as soon as it came into 

 my possession, I put it in " pickle," — i.e. a strong solution of 

 alkali, — brushed off the paint, and placed it in my museum, 

 where it is now. 



On the left hand of the illustration on page 514 is given 

 a sort of map or chart of the human Ear, with its internal 

 Drum, or Tympanum, as it is scientifically termed. 



It is by the vibration of this Drum that hearing is made 

 possible, the vibrations of the air being transmitted to the 

 Drum by means of a beautiful bony apparatus, termed the 

 Hammer and Anvil {Malleus et Incus). Sometimes the action 

 of the Drum is partially checked, and then the sufferer is 

 said to be " hard of hearing." Sometimes it is broken, or its 

 action totally clogged, and then he is said to be "stone 

 deaf." There have been cases where an artificial tympanum 

 has been inserted, and answered its purpose fairly well. 



The String and Reed. 



It has previously been mentioned that all sounds are owing 

 to vibrations of the air. But there are many ways of producing 

 these vibrations, and each mode gives a different quality of 

 tone. We have already seen, by means of the drum, how 

 sound is produced by percussion. We shall now see how 

 sounds can be produced by the vibrations of a String. 



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