Parallel motion

Parallel Par"al*lel, a. [F. parall[`e]le, L. parallelus, fr. Gr. ?; para` beside + ? of one another, fr. ? other, akin to L. alius. See {Alien}.] 1. (Geom.) Extended in the same direction, and in all parts equally distant; as, parallel lines; parallel planes. [1913 Webster]

Revolutions . . . parallel to the equinoctial. --Hakluyt. [1913 Webster]

Note: Curved lines or curved planes are said to be parallel when they are in all parts equally distant. [1913 Webster]

2. Having the same direction or tendency; running side by side; being in accordance (with); tending to the same result; -- used with to and with. [1913 Webster]

When honor runs parallel with the laws of God and our country, it can not be too much cherished. --Addison. [1913 Webster]

3. Continuing a resemblance through many particulars; applicable in all essential parts; like; similar; as, a parallel case; a parallel passage. --Addison. [1913 Webster]

{Parallel bar}. (a) (Steam Eng.) A rod in a parallel motion which is parallel with the working beam. (b) One of a pair of bars raised about five feet above the floor or ground, and parallel to each other, -- used for gymnastic exercises.

{Parallel circles of a sphere}, those circles of the sphere whose planes are parallel to each other.

{Parallel columns}, or {Parallels} (Printing), two or more passages of reading matter printed side by side, for the purpose of emphasizing the similarity or discrepancy between them.

{Parallel forces} (Mech.), forces which act in directions parallel to each other.

{Parallel motion}. (a) (Mach.) A jointed system of links, rods, or bars, by which the motion of a reciprocating piece, as a piston rod, may be guided, either approximately or exactly in a straight line. --Rankine. (b) (Mus.) The ascending or descending of two or more parts at fixed intervals, as thirds or sixths.

{Parallel rod} (Locomotive Eng.), a metal rod that connects the crank pins of two or more driving wheels; -- called also {couping rod}, in distinction from the connecting rod. See Illust. of {Locomotive}, in App. -- {Parallel ruler}, an instrument for drawing parallel lines, so constructed as to have the successive positions of the ruling edge parallel to each other; also, one consisting of two movable parts, the opposite edges of which are always parallel.

{Parallel sailing} (Naut.), sailing on a parallel of latitude.

{Parallel sphere} (Astron. & Geog.), that position of the sphere in which the circles of daily motion are parallel to the horizon, as to an observer at either pole.

{Parallel vise}, a vise having jaws so guided as to remain parallel in all positions. [1913 Webster]