Water tube

Tube Tube, n. [L. tubus; akin to tuba a trumpet: cf F. tube.] 1. A hollow cylinder, of any material, used for the conveyance of fluids, and for various other purposes; a pipe. [1913 Webster]

2. A telescope. ``Glazed optic tube.'' --Milton. [1913 Webster]

3. A vessel in animal bodies or plants, which conveys a fluid or other substance. [1913 Webster]

4. (Bot.) The narrow, hollow part of a gamopetalous corolla. [1913 Webster]

5. (Gun.) A priming tube, or friction primer. See under {Priming}, and {Friction}. [1913 Webster]

6. (Steam Boilers) A small pipe forming part of the boiler, containing water and surrounded by flame or hot gases, or else surrounded by water and forming a flue for the gases to pass through. [1913 Webster]

7. (Zo["o]l.) (a) A more or less cylindrical, and often spiral, case secreted or constructed by many annelids, crustaceans, insects, and other animals, for protection or concealment. See Illust. of {Tubeworm}. (b) One of the siphons of a bivalve mollusk. [1913 Webster]

8. (Elec. Railways) A tunnel for a tube railway; also (Colloq.), a tube railway; a subway. [Chiefly Eng.]

Note: In the New York area, the subways running under the Hudson River are sometimes referred to as the tube. [Webster 1913 Suppl. +PJC]

{Capillary tube}, a tube of very fine bore. See {Capillary}.

{Fire tube} (Steam Boilers), a tube which forms a flue.

{Tube coral}. (Zo["o]l.) Same as {Tubipore}.

{Tube foot} (Zo["o]l.), one of the ambulacral suckers of an echinoderm.

{Tube plate}, or {Tube sheet} (Steam Boilers), a flue plate. See under {Flue}.

{Tube pouch} (Mil.), a pouch containing priming tubes.

{Tube spinner} (Zo["o]l.), any one of various species of spiders that construct tubelike webs. They belong to {Tegenaria}, {Agelena}, and allied genera.

{Water tube} (Steam Boilers), a tube containing water and surrounded by flame or hot gases. [1913 Webster]