Chapter XVII

.--WHY THE WIND BLOWS.

Why the wind blows--Land and sea breezes--Light air and moisture--The barometer--The column barometer--The wheel barometer--A very simple barometer--The aneroid barometer--Barometers and weather--The diving-bell--The diving-dress--Air-pumps--Pneumatic tyres--The air-gun--The self-closing door-stop--The

## action of wind on oblique surfaces--The balloon--The

flying-machine 322

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