\At`mos*pher"ic\, Atmospherical \At`mos*pher"ic*al\,
a. [Cf. F. atmosph['e]rique.]
1. Of or pertaining to the atmosphere; of the nature of, or
   resembling, the atmosphere; as, atmospheric air; the
   atmospheric envelope of the earth.
2. Existing in the atmosphere.
         The lower atmospheric current.        --Darwin.
3. Caused, or operated on, by the atmosphere; as, an
   atmospheric effect; an atmospheric engine.
4. Dependent on the atmosphere. [R.]
         In am so atmospherical a creature.    --Pope.
{Atmospheric engine}, a steam engine whose piston descends by
   the pressure of the atmosphere, when the steam which
   raised it is condensed within the cylinder. --Tomlinson.
{Atmospheric line} (Steam Engin.), the equilibrium line of an
   indicator card. Steam is expanded ``down to the
   atmosphere'' when its pressure is equal to that of the
   atmosphere. (See {Indicator card}.)
{Atmospheric pressure}, the pressure exerted by the
   atmosphere, not merely downwards, but in every direction.
   In amounts to about 14.7 Ibs. on each square inch.
{Atmospheric railway}, one in which pneumatic power, obtained
   from compressed air or the creation of a vacuum, is the
   propelling force.
{Atmospheric tides}. See under {Tide}.