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.
Here are entered works on the planning, design, construction, and operation of works of various kinds for the purpose of modifying natural river conditions to better serve human needs.
Here are entered works on the prevention of beach erosion. Works on coast changes resulting from erosion or other causes are entered under Coast changes. Works on the erosion of beaches are entered under Beach erosion.