CRANE.| Prospecting and Boring for Mineral Waters. 111 
which is operated by a drum driven by the power turning the 
drill. (Plate IX.) The feed is thus regulated by the drum, 
while the turning of the rod is accomplished by a simple ar- 
rangement of belting and gears. (Plate X.) The jetting-head 
is provided with a ball-bearing swivel, thus allowing the rod to 
turn independent of the water connection and supporting at- 
tachment. The surface plant is thus markedly different from 
that of a diamond drill, which is largely necessitated by the size 
and weight of the rod. The size of the bore for deep holes 
ranges from 2¢ to 10 inches in diameter. As no diamonds are 
required, there is no reason for taking out small cores. 
The bit or cutter is a metallic shell, with peculiar teeth in 
one end, and a thread cut in the other for screwing into the 
core-barrel. 
The core-barrel is a tube, which is always larger in diameter 
than the drill-rods, but of the same outside diameter as the 
main body of the cutter. 
The drill-rods are tubes which screw into the upper end of 
the core-barrel by means of a reducing plug, and extend down- 
ward from the surface. 
The calyx is also a tube or series of tubes equal in diameter 
to the core-barrel. It surrounds the lower drill-rod, rests on 
the reducing plug, and is open at the upper end, thus leaving a 
space between the drill-rod and the inside of the calyx. The 
purpose of this space is explained. further on. 
Method of Operation of Calyx Drill.—The principle involved 
in the calyx drill is to all intents and purposes the same as in 
the diamond drill. In the case of the former, however, drilling 
is accomplished by means of steel teeth, instead of with dia- 
monds. Here, too, the torsion of the drill-rod is brought into 
play, the teeth catching on the bottom of the hole, holding until 
by the torsion or twist of the rod sufficient energy is accumu- 
lated to overcome the bite. The instant that the surface strain 
exceeds the resistance of the turning below, the cutter tears 
loose, cutting fragments from the groove in which it rests. The 
strain being relieved, the cutter again comes to rest and is again 
torn from its bite. The repetition of these movements produces 
