airtube

1. Mech. A tube constructed for the reception or pa age of air. that series of air-cells a ociated by dependence on a single terminal air - tube."-Todd & Bowman : Phys. Anat., vol. ii., p. 388. "By this structure the most delicate and invisible ramifications of the air - tubes may be easily recognised under the microscope."- Owen : Invertebrata , § xvii. air-valve, s. A valve commonly applied to a boiler to guard against the creation of a vacuum within it when the steam inside is condensed.