I took him to my room, and placed him in a water-tight box, in which I fashioned an artificial bog, in the hope that he would confirm my testimony by his piping.

Air-tight alibis.

In another locker was a kit of carpenter's tools, which would come in very handy if they were to remain long on the island, and in another water-tight compartment the captain had stowed his chronometer, his instruments for finding the position of the ship, and some charts.

I brought the burglar into the laboratory and deposited him in the tank, shutting the air-tight lid and securing it with a padlock.

The notebook was safe in a water-tight pocket.

If the skin be covered with some air-tight substance like a coating of varnish, its functions are completely arrested.