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Ver·ti·cal a.

1. Of or pertaining to the vertex; situated at the vertex, or highest point; directly overhead, or in the zenith; perpendicularly above one.

*Charity . . . is the vertical top of all religion.* --*Jer. Taylor.*

2. Perpendicular to the plane of the horizon; upright; plumb; as, a vertical line.

**Vertical angle** Astron. & Geod., an angle measured on a vertical circle, called an angle of __elevation__, or __altitude__, when reckoned from the horizon upward, and of __depression__ when downward below the horizon.

**Vertical anthers** Bot., such anthers as stand erect at the top of the filaments.

**Vertical circle** Astron., an azimuth circle. See under Azimuth.

**Vertical drill**, an upright drill. See under Upright.

**Vertical fire** Mil., the fire, as of mortars, at high angles of elevation.

**Vertical leaves** Bot., leaves which present their edges to the earth and the sky, and their faces to the horizon, as in the Australian species of Eucalyptus.

**Vertical limb**, a graduated arc attached to an instrument, as a theodolite, for measuring vertical angles.

**Vertical line**. (a) Dialing A line perpendicular to the horizon. (b) Conic Sections A right line drawn on the vertical plane, and passing through the vertex of the cone. (c) Surv. The direction of a plumb line; a line normal to the surface of still water. (d) Geom., Drawing, etc. A line parallel to the sides of a page or sheet, in distinction from a __horizontal line__ parallel to the top or bottom.

**Vertical plane**. (a) Conic Sections A plane passing through the vertex of a cone, and through its axis. (b) Projections Any plane which passes through a vertical line. (c) Persp. The plane passing through the point of sight, and perpendicular to the ground plane, and also to the picture.

**Vertical sash**, a sash sliding up and down. Cf. French sash, under 3d Sash.

**Vertical steam engine**, a steam engine having the crank shaft vertically above or below a vertical cylinder.