magnetic compass
111compass course — The course that a pilot should fly to maintain a desired track. A compass course is equal to the magnetic course plus or minus deviation …
112compass — noun 1》 an instrument containing a magnetized pointer which shows the direction of magnetic north and bearings from it. 2》 (also compasses) an instrument for drawing circles and arcs and measuring distances between points, consisting of two arms… …
113compass card — com′pass card n. naut. navig. a circular card displaying the points of the compass that rotates freely to point to magnetic north • Etymology: 1870–75 …
114compass — [13] The notion underlying compass is of ‘measuring out with paces’. It originated as a verb, Vulgar Latin *compassāre ‘pace out’, a compound formed from the Latin intensive prefix com and passus (source of English pace). This passed into Old… …
115compass course — noun : the course with respect to true north in which a ship or an aircraft is intended to travel * * * Naut. a course whose bearing is relative to the meridian as given by the navigator s compass, no compensation being made for variation or… …
116magnetic north — noun Date: 1812 the northerly direction in the earth s magnetic field indicated by the north seeking pole of a compass needle …
117magnetic course — Navig. a course whose bearing is given relative to the magnetic meridian of the area. Cf. compass course, true course. * * * …
118magnetic needle — a slender magnetized steel rod that, when adjusted to swing in a horizontal plane, as in a compass, indicates the direction of the earth s magnetic fields or the approximate position of north and south. [1840 50] * * * …
119magnetic reversal — noun Any of several reversals in the polarity of the Earths magnetic field (such that a compass points South) that have happened over geologic time …
120magnetic dip — noun The angle between magnetic north and the horizontal (as shown by a compass held vertically) …
