CraNE.| Prospecting and Boring for Mineral Waters. 109 
from the bit up, as follows: The bit, the core-lifter, the core- 
barrel. 
The bit is the part which contains the diamonds. The ar- 
rangement of the diamonds on the bit 1s quite varied, the main 
idea being to so place them as to cause their respective tracks 
or courses to lap, thus eveningly and uniformly wearing away 
the rock. It is common practice to provide grooves in the 
sides and edge of the bit to insure a more even flow of water 
for removing the cuttings from the bottom of the hole. The 
action of the diamond drill upon the rock is not cutting, but 
grinding—the diamonds being set so as to slide, and when 
forced down will drag out or grind a groove. The diamonds 
or stones used for drilling are borts (defective brilliants) and 
carbons (colored diamonds), and are obtained largely from 
South America. 
Above the bit is the core-lifter, of which there are two general 
forms, namely: The cossette and the split-ring. The cossette 
form consists of a series of spines, which are attached at the 
lower end around the inside of the body of the lifter. The core 
in rising, or the drill in passing downward, raises them in a 
vertical position, but when the operation is reversed, the drill- 
rod and lifter being raised, they catch in the sides of the core 
and prevent its withdrawal. The split-ring core-lifter is, as the 
name indicates, a split-ring which encloses the core. The ring 
is tapering and rests in a tapering recess, which is an enlarge- 
ment of the hole through the section of the rod which consti- 
tutes the body of the lifter. As the drill works its way 
downward the core rises through the core-lifter, pushing the 
split-ring in the upper and larger part of the tapering recess, 
thus allowing it to expand to its normal shape, and presenting 
practically no resistance to the passage of the core through it. 
When, however, the full length of the feed is reached, and it is 
desired to raise the core, the split-ring attached to the core is 
drawn downward into the narrowing recess by the raising of 
the drill-rod, and is consequently caused to tighten its grip on 
the core. To prevent slipping, the inner surface of the split- 
ring is provided with teeth, which point upward and inward. 
