Singstad subsequently declared that the ventilation system was well equipped to ventilate the tunnel air. The eaves overhang may also shelter openings to ventilate the roof space. These tubes enable one to ventilate both lungs, or either lung independently. Bowfin have two distinct air-breathing mechanisms used to ventilate the gas bladder. What is known is that yawning does ventilate all the alveoli in the lungs. Later kilns were built above ground to be easier to maintain and ventilate. He advised his readers to ventilate sickrooms and to seek fresh air in cities. Later, they may ventilate the hive or guard the entrance. The nurses had opened most of those portholes to ventilate the wards, against standing orders. As with many large liners, the third funnel was used to ventilate the engines rooms. To solve the problem, Sam carves out holes which ventilate the house. The first priority was to ventilate the workings. The explosion blew up the fan used to ventilate Number 4.