Definition of "water-tube" [water-tube]

• A pipe for rainwater. (noun)
• One of a set of tubes which open upon the exterior of various invertebrates, and into which water may enter. (noun)

The Century Dictionary (Public Domain)

• "The principle was that of the 'water-tube' boilers of the present day."
• "The reason for this is found in the difficulties involved in the design and construction of water-tube boilers, which design and construction required a high class of engineering and workmanship, while the plain cylindrical boiler is comparatively easy to build."
• "The factor of safety of the boiler parts which come in contact with the most intense heat in water-tube boilers can be made much higher than would be practicable in a shell boiler."