Dip

(dip.) [A.S. dyppan. ] (Mag.) The angle which the direction of a magnetized needle, free to move in the plane of the magnetic meridian, makes with the horizontal plane at the place. Let a magnetized needle, free to turn in a vertical plane, be placed so that that plane may coincide with the plane of the magnetic meridian, it will be found that in most localities one end or other will dip downward, and thus the direction of the needle will make a certain angle with the horizontal plane at the place. This angle is called the angle of dip, or the magnetic dip.-(Geol.) The inclination of a stratum of rock; its amount is measured by the angle it makes with the horizontal plane. Strike is the direction of the stratum at right angles to the dip. The ridge of a house-roof represents the strike, while the sloping slates represent the dip. 1 [s. 289]