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Having all the planes required by complete symmetry, -- in opposition to hemihedral.

Presenting hemihedral forms, in which all the sectants have halt the whole number of planes. Dana.

hod of constructing geographical charts or maps, so that the surfaces, as delineated on a plane, have the same relative size as the real surfaces; that is, so that the relative actual areas of the different countries are accurately represented by the corresponding portions of the map.

A plane passing through the eye of the spectator and at right angles to the vertical at a given place; a plane tangent to the earth's surface at that place; called distinctively the sensible horizon.

Measured or contained in a plane of the horizon; as, horizontal distance. Horizontal drill, a drilling machine having a horizontal drill spindle. -- Horizontal engine, one the piston of which works horizontally. -- Horizontal fire (Mil.), the fire of ordnance and small arms at point-blank range or at low angles of el…

ay. -- Horse run (Civil Engin.), a device for drawing loaded wheelbarrows up an inclined plane by horse power. -- Horse sense, strong common sense. [Colloq. U.S.] -- Horse soldier, a cavalryman. -- Horse sponge (Zoöl.), a large, coarse, commercial sponge (Spongia equina). -- Horse stinger (Zoöl.), a large dragon fl…

f 15º, or one hour, each. (b) A circle upon an equatorial telescope lying parallel to the plane of the earth's equator, and graduated in hours and subdivisions of hours of right ascension. (c) A small brass circle attached to the north pole of an artificial globe, and divided into twenty-four parts or hours. It is used…

or house of life, downward, or in the direction of the earth's revolution, the stars and planets passing through them in the reverse order every twenty- four hours.

To smooth; to plane; as, to howel a cask.

A curve formed by a section of a cone, when the cutting plane makes a greater angle with the base than the side of the cone makes. It is a plane curve such that the difference of the distances from any point of it to two fixed points, called foci, is equal to a given distance. See Focus. If the cutting plane be produce…

A surface of the second order, which is cut by certain planes in hyperbolas; also, the solid, bounded in part by such a surface. Hyperboloid of revolution, an hyperboloid described by an hyperbola revolving about one of its axes. The surface has two separate sheets when the axis of revolution is the transverse axis, bu…

aketh an ill seat, but ill ways, ill markets, and ill neighbors. Bacon. There 's some ill planet reigns. Shak.

The angle made by two lines or planes; as, the inclination of the plane of the earth's equator to the plane of the ecliptic is about 23º 28'; the inclination of two rays of light.

An inclined plane; an ascent o

Making an angle with some line or plane; -- said of a line or plane.

An apparatus to determine the inclination of the earth's magnetic force to the plane of the horizon; -- called also inclination compass, and dip circle.

A certain conic section supposed to be drawn in the tangent plane to any surface, and used to determine the accidents of curvature of the surface at the point of contact. The curve is similar to the intersection of the surface with a parallel to the tangent plane and indefinitely near it. It is an ellipse when the curv…

An irregularity, or a deviation, in the motion of a planet or satellite from its uniform mean motion; the amount of such deviation.

Nearer the sun than the earth is; as, the inferior or interior planets; an inferior conjunction of Mercury or Venus.

That part of a line, or of a plane, or of space, which is infinitely distant. In modern geometry, parallel lines or planes are sometimes treated as lines or planes meeting at infinity. Circle at infinity, an imaginary circle at infinity, through which, in geometry of three dimensions, every sphere is imagined to pass.…