|
magic square: square grid with a number in each cell for which the sum of each row, column and diagonal is the same.
|
magnetic compass: instrument indicating directions by a magnetic needle, see article on the compass.
|
magnetic deviation: the angle between geographical north and the direction indicated by a compass needle.
|
magnitudes: numbers in a scale of the relative brightnesses of the stars, 1 being the brightest.
|
mariner's astrolabe: altitude-measuring instrument for finding latitude at sea, having a heavy brass or bronze ring, suspended by a shackle and ring, with a degree scale and a centrally-pivoted alidade.
|
mater: part of an astrolabe, see article on the astrolabe.
|
mathematical compendium: compound instrument for performing various functions in practical mathematics.
|
