400 EASTERN ETHIOPIA xxxi 



ivory" (l Kings x. 18) must have been a cunning- 

 piece of work ; it was overlaid with tlie best gold 

 and ornamented with figures of lions. Ivory is a 

 material frec|uently mentioned in the Old Testament. 



Layard during his excavations at Nineveh found some 

 pieces of ivory (now preserved in the British Museum) 

 which prol3al)ly existed nearly a thousand years before 

 Christ. 



Among the many interesting objects made from 

 elephant-tusks are billiard balls. A good ball should 

 be perfectly spherical, but it continually tends to 

 become ovoid. Tusks recently removed from elephants 

 are described as " green " ; as the ivory dries it whitens, 

 tends to liecome brittle and break up into concentric 

 layers. AA^hen a tusk is divided transversely the cut 

 surface has an elliptical outline, and in the middle of the 

 section there is a rounded piece of secondary dentine 

 re])resenting the remains of the pulp chamber, this 

 ivory-turners call the "nerve." Ivory is deposited 

 in layers, therefore the cut surface offers a series of 

 concentric rings especially obvious in green tusks. 

 The outer layer is technically known as "bark." As 

 ivory dries it shrinks and experience has taught the 

 ivory-turner that a tusk shrinks more in width than in 

 length. To meet this peculiarity the best billiard 

 balls are prepared from tusks which have a diameter 

 very little greater than that of the ball. In such 

 circumstances the shrinking will be fairly uniform. 

 The tusks of cow-elephants are preferred for making 

 liilliard balls, especially those which weigh about twelve 

 to sixteen pounds : these arc known in the sale-room 

 as scrivelloes. They are not so curved as larger 

 tusks and the so-called nerve is less conspicuous, and 

 in selectino' tusks for makins; billiard balls it is 

 necessary to take those in which the nerve is central ; 

 otherwise the ball will have a bias and be untrue. 

 The remains of the pulp chamber can always be 

 detected in a billiard ball ; the better the ball the 



