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