DIVING BELL

ac apparatus to enab! - to| persona to remain onder water a con ed |derable time. Two principles are inma-| volved in its working—(1) the pre ure in | that a liquid can exert at any point within ne, | itself is proportional to the depth of that ya- | point; and (2) the pre ure that a gas can ng | exert is proportional to ita density, which Mr | increases ax the bulk or volume of the as's ame amount of gas decreases. If an > [s. 123]