Section

(a)

* In mechanical drawing, as in these Illustrations of a cannon, a longitudinal section (a) usually represents the object as cut through its center lengthwise and vertically; a cross or transverse section (b), as cut crosswise and vertically; and a horizontal section (c), as cut through its center horizontally. Oblique sections are made at various angles. In architecture, a vertical section is a drawing showing the interior, the thickness of the walls, etc., as if made on a vertical plane passed through a building.

Angular sections (Math.), a branch of analysis which treats of the relations of sines, tangents, etc., of arcs to the sines, tangents, etc., of their multiples or of their parts. [R.] -- Conic sections. (Geom.) See under Conic. -- Section liner (Drawing), an instrument to aid in drawing a series of equidistant parallel lines, -- used in representing sections. -- Thin section, a section or slice, as of mineral, animal, or vegetable substance, thin enough to be transparent, and used for study under the microscope.

Syn. -- Part; portion; division. -- Section, Part. The English more commonly apply the word section to a part or portion of a body of men; as, a section of the clergy, a small section of the Whigs, etc. In the United States this use is less common, but another use, unknown or but little known in England, is very frequent, as in the phrases "the eastern section of our country," etc., the same sense being also given to the adjective sectional; as, sectional feelings, interests, etc.