400 
EASTERN ETHIOPIA 
XXXI 
ivory” (l Kings x. 18 ) must have been a cunning 
piece of work; it was overlaid with the best gold 
and ornamented with figures of lions. Ivory is a 
material frequently mentioned in the Old Testament. 
Layard during his excavations at Nineveh found some 
]3ieces of ivory (now preserved in the British Museum) 
which probably existed nearly a thousand years before 
CJirist. 
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 become brittle and break up into concentric 
layers. When 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 
representing 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 
billiard balls, especially those which weigh about twelve 
to sixteen pounds : these are 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 makino; billiard balls it is 
necessary to take those in which the nerve is central ; 
otherwise the ball will have a bias and be untrue. 
^Idie remains of the pulp chamber can always be 
detected in a billiard ball; the better the ball the 
