siphon barometer

2 definitions found

siphon barometer - Collaborative International Dictionary of English v.0.48 :

  Siphon \Si"phon\, n. [F. siphon, L. sipho, -onis, fr. Gr. ??? a
     siphon, tube, pipe.]
     1. A device, consisting of a pipe or tube bent so as to form
        two branches or legs of unequal length, by which a liquid
        can be transferred to a lower level, as from one vessel to
        another, over an intermediate elevation, by the action of
        the pressure of the atmosphere in forcing the liquid up
        the shorter branch of the pipe immersed in it, while the
        continued excess of weight of the liquid in the longer
        branch (when once filled) causes a continuous flow. The
        flow takes place only when the discharging extremity of
        the pipe ia lower than the higher liquid surface, and when
        no part of the pipe is higher above the surface than the
        same liquid will rise by atmospheric pressure; that is,
        about 33 feet for water, and 30 inches for mercury, near
        the sea level.
        [1913 Webster]
  
     2. (Zool.)
        (a) One of the tubes or folds of the mantle border of a
            bivalve or gastropod mollusk by which water is
            conducted into the gill cavity. See Illust. under
            Mya, and Lamellibranchiata.
        (b) The anterior prolongation of the margin of any
            gastropod shell for the protection of the soft siphon.
        (c) The tubular organ through which water is ejected from
            the gill cavity of a cephaloid. It serves as a
            locomotive organ, by guiding and confining the jet of
            water. Called also siphuncle. See Illust. under
            Loligo, and Dibranchiata.
        (d) The siphuncle of a cephalopod shell.
        (e) The sucking proboscis of certain parasitic insects and
            crustaceans.
        (f) A sproutlike prolongation in front of the mouth of
            many gephyreans.
        (g) A tubular organ connected both with the esophagus and
            the intestine of certain sea urchins and annelids.
            [1913 Webster]
  
     3. A siphon bottle.
        [1913 Webster]
  
     Inverted siphon, a tube bent like a siphon, but having the
        branches turned upward; specifically (Hydraulic
        Engineering), a pipe for conducting water beneath a
        depressed place, as from one hill to another across an
        intervening valley, following the depression of the
        ground.
  
     Siphon barometer. See under Barometer.
  
     Siphon bottle, a bottle for holding aerated water, which is
        driven out through a bent tube in the neck by the gas
        within the bottle when a valve in the tube is opened; --
        called also gazogene, and siphoid.
  
     Siphon condenser, a condenser for a steam engine, in which
        the vacuum is maintained by the downward flow of water
        through a vertical pipe of great height.
  
     Siphon cup, a cup with a siphon attached for carrying off
        any liquid in it; specifically (Mach.), an oil cup in
        which oil is carried over the edge of a tube in a cotton
        wick, and so reaches the surface to be lubricated.
  
     Siphon gauge. See under Gauge.
  
     Siphon pump, a jet pump. See under Jet, n.
        [1913 Webster]

  Barometer \Ba*rom"e*ter\, n. [Gr. ba`ros weight + -meter: cf. F.
     barom[`e]tre.]
     An instrument for determining the weight or pressure of the
     atmosphere, and hence for judging of the probable changes of
     weather, or for ascertaining the height of any ascent.
     [1913 Webster]
  
     Note: The barometer was invented by Torricelli at Florence
           about 1643. It is made in its simplest form by filling
           a graduated glass tube about 34 inches long with
           mercury and inverting it in a cup containing mercury.
           The column of mercury in the tube descends until
           balanced by the weight of the atmosphere, and its rise
           or fall under varying conditions is a measure of the
           change in the atmospheric pressure. At the sea level
           its ordinary height is about 30 inches (760
           millimeters). See Sympiesometer. --Nichol.
           [1913 Webster]
  
     Aneroid barometer. See Aneroid barometer, under
        Aneroid.
  
     Marine barometer, a barometer with tube contracted at
        bottom to prevent rapid oscillations of the mercury, and
        suspended in gimbals from an arm or support on shipboard.
        
  
     Mountain barometer, a portable mercurial barometer with
        tripod support, and long scale, for measuring heights.
  
     Siphon barometer, a barometer having a tube bent like a
        hook with the longer leg closed at the top. The height of
        the mercury in the longer leg shows the pressure of the
        atmosphere.
  
     Wheel barometer, a barometer with recurved tube, and a
        float, from which a cord passes over a pulley and moves an
        index.
        [1913 Webster] Barometric