104 University Geological Survey of Kansas. 
ened by diagonal braces. The derrick supports two sheaves at 
the top, one for the drill and the other for the sand-pump rope. 
Off to one side of the derrick, at a distance of sixty to seventy- 
five feet, is placed an engine, usually of the traction-engine 
type. From this engine a belt passes to a power- or drive- 
wheel, supported by a framework which also supports a reel 
employed in driving the sand-pump. 
To the derrick base on a suitable support is hung the walk- 
ing-beam, one end of which is connected by a pitman to the 
drive-wheel, while the other end is fastened to the rope, when 
drilling, by means of the temper-screw. On the opposite side of 
the derrick from the walking-beam is placed the bull-wheel, 
which is employed in raising and lowering the drill in the hole. 
When notin use, the sand-pump stands to one side within the der- 
rick ; when used, it is employed alternately with the drill—that 
is, after drilling for a certain length of time the drill is removed 
and the sand-pump lowered to remove the water and cuttings 
from the hole, and thus facilitate the drilling operations. It is 
operated by a friction-wheel working on the rim of the power- 
wheel, which can be thrown on or off at will. 
The temper-screw consists of a split-nut fastened to the lower 
end of a steel frame, four feet six inches long, which is fastened 
to the walking-beam. In the split-nut a long steel screw op- 
erates. At the lower end of the frame is a clamp enclosing the 
split-nut, which, when tightened, forces the two parts of the 
nut together, making it in reality solid or like one piece. 
Screwing into the nut is a long, steel feed-screw, to the lower 
end of which is a ball-bearing swivel, linked to which is a 
clamp for holding the rope. A cross-brace is set-screwed to the 
feed-screw just above the swivel, by means of which the screw 
is fed through the nut, thereby lowering the drill in the hole, 
thus constituting the action of feeding. The object of the split- 
nut is to facilitate the setting back of the frame at the end of 
the feed; that is, by unclasping the split-nut the frame can be 
slipped down upon the feed-screw ; otherwise it would have to 
be screwed back, which would necessitate considerable time and 
consequent delay. 
