Train crews, and introduce procedures to make drill work more safe and effective. Observe pressure gauge and move throttles and levers in order to control the speed of rotary tables, and to regulate pressure of tools at bottoms of boreholes. Count sections of drill rod in order to determine depths of boreholes. Push levers and brake pedals in order to control gasoline, diesel, electric, or steam draw works that lower and raise drill pipes and casings in and out of wells. Connect sections of drill pipe, using hand tools and powered wrenches and tongs. Maintain records of footage drilled, location and nature of strata penetrated, materials and tools used, services rendered, and time required. Maintain and adjust machinery in order to ensure proper performance. Start and examine operation of slush pumps in order to ensure circulation and consistency of drilling fluid or mud in well. Locate and recover lost or broken bits, casings, and drill pipes from wells, using special tools. Weigh clay, and mix with water and chemicals to make drilling mud. Direct rig crews in drilling and other activities, such as setting up rigs and completing or servicing wells. Monitor progress of drilling operations, and select and change drill bits according to the nature of strata, using hand tools. Repair or replace defective parts of machinery, such as rotary drill rigs, water trucks, air compressors, and pumps, using hand tools. Clean and oil pulleys, blocks, and cables. Bolt together pump and engine parts, and connect tanks and flow lines. Remove core samples during drilling in order to determine the nature of the strata being drilled.