Gerry Bailey Felicia Law Illustrations by Iralu Long ago The early ways we moved around our planet and the science that let us ACTION
2 Birchbark canoe Travois Light aircraft York boat Chariot Litter Trading ships Motor car Barge Windjammer Steam train Covered wagon Penny farthing Phaeton Gondola Trireme Montgolfier balloon Paddle boat 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 Contents sail shape steam engine Center OF GRAVITY SPOKED WHEEL SPRINGS STREAMLINING KNOTS EXPANDING AIR PADDLE wheel WOOD BARK FRICTION PROPELLERS KINETIC ENERGY wheel and axle gravity RUDDER combustion engine locks ACTION
40 42 44 Horse bus horsepower Coracle UPTHRUST Glossary 46 Index 48 Credits We have come a long way since the invention of the wheel although many forms of transport still rely on its use However nowadays we expect to move from place to place at speed and in comfort To do work machines need energy The energy that machines use may be electrical energy or chemical energy from fossil fuels such as gasoline or diesel Power is the rate at which work is done It is measured in watts or horsepower Power can be as little as the power from a sedan chair porter’s arms or as much as the water power turning the wheel of a paddle boat Let’s look at some old machines that paved the way for the exciting inventions of today and the science that made it possible 3
