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ll from the angles of a triangle upon the opposite sides, or the sides produced, mutually intersect.

Right-angled; rectangular; as, an orthogonal intersection of one curve with another. Orthogonal projection. See under Orthographic.

A kind of curve; one of the conic sections formed by the intersection of the surface of a cone with a plane parallel to one of its sides. It is a curve, any point of which is equally distant from a fixed point, called the focus, and a fixed straight line, called the directrix. See Focus.

A mock moon; an image of the moon which sometimes appears at the point of intersection of two lunar halos. Cf. Parhelion.

hority over all its generations. Patriarchal cross (Her.), a cross, the shaft of which is intersected by two transverse beams, the upper one being the smaller. See Illust.

A number of lines that intersect in one point, the point of intersection being called the pencil point.

A figure composed of two equilateral triangles intersecting so as to form a six-pointed star, -- used in early ornamental art, and also with superstitious import by the astrologers and mystics of the Middle Ages.

fixed conventional place for reference, or zero of reckoning, in the heavens, usually the intersection of two or more great circles of the sphere, and named specifically in each case according to the position intended; as, the equinoctial points; the solstitial points; the nodal points; vertical points, etc. See Equino…

incipal axes of a quadric (Geom.), three lines in which the principal planes of the solid intersect two and two, as in an ellipsoid. -- Principal challenge. (Law) See under Challenge. -- Principal plane. See Plane of projection (a), under Plane. -- Principal of a quadric (Geom.), three planes each of which is at rig…

punctual sun." Cowper. These sharp strokes [of a pendulum], with their inexorably steady intersections, so agree with our successive thoughts that they seem like the punctual stops counting off our very souls into the past. J. Martineau.

The angle which the plane of the dial makes with a vertical plane which it intersects in a horizontal line. Brande & C.

The intersection of two surface forming a salient angle, especially the angle at the top between the opposite slopes or sides of a roof or a vault.

church, over which the rood was placed. Fairholt. -- Rood tower (Arch.), a tower at the intersection of the nave and transept of a church; -- when crowned with a spire it was called also rood steeple. Weale. -- Rood tree, the cross. [Obs.] "Died upon the rood tree." Gower.

m.), the points on a line, infinite in number, as the points in which a pencil of rays is intersected by a line.

A cutting; an intersection; as, the point of secancy of one line by another. [R.] Davies & Peck (Math. Dict. ).

The description or representation of anything as it would appear if cut through by any intersecting plane; depiction of what is beyond a plane passing through, or supposed to pass through, an object, as a building, a machine, a succession of strata; profile.

A flattened concretionary nodule, usually of limestone, intersected within by cracks which are often filled with calcite, barite, or other minerals.

nerally resembling bevel gearing, for connecting two shafts that are neither parallel nor intersecting, and in which the teeth slant across the faces of the gears. -- Skew surface (Geom.), a ruled surface such that in general two successive generating straight lines do not intersect; a warped surface; as, the helicoid…

a. -- Solid problem (Geom.), a problem which can be construed geometrically, only by the intersection of a circle and a conic section or of two conic sections. Hutton. -- Solid square (Mil.), a square body or troops in which the ranks and files are equal.

triangle,re on the surface of a sphere, bounded by the arcs of three great circles which intersect each other. -- Spherical trigonometry. See Trigonometry. -- Spher"ic*al*ly, adv. -- Spher"ic*al*ness, n.