ORRERY n.
An apparatus which illustrates, by the revolution of balls moved by wheelwork, the relative size, periodic motions, positions, orbits, etc., of bodies in the solar system.
PARALLEL a.
el 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…
PAWL n.
chine, adapted to fall into notches, or interdental spaces, on another part, as a ratchet wheel, in such a manner as to permit motion in one direction and prevent it in the reverse, as in a windlass; a catch, click, or detent. See Illust. of Ratchet Wheel. [Written also paul, or pall.] Pawl bitt (Naut.), a heavy timber…