Here are entered works on the operation of cutting holes in earth or rocks, in order to determine the nature of the strata penetrated, or to furnish an outlet for water, oil, or gas. Works on the drilling and boring of holes in metal, wood, and other materials, as carried on in workshops, etc., for construction or manufacturing purposes are entered under Drilling and boring.
Works designed to help prepare for examinations or courses of study. For practice problems and exercises designed to develop and improve skills in an area of study, see Problems and exercises.
