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 books 10 centimeters or less in both height and width. Actual specimens of such books are entered under Miniature books--Specimens, a form heading assigned without geographic subdivision.
