Book excerpt: Award-winning artist David Macaulay introduces readers to his hilarious new creations, Sloth and Sengi, in How Machines Work: Zoo Break! Get your cogs turning with these mega machines! This amazing, award-winning visual guide showcases the science and technology behind the most important machines ever invented. How Machines Work is a unique book full of inspiring illustrations by award-winning artist David Macaulay and packed with interactive elements, including press-out models, pop-ups, and pull-outs. Sloth and his sidekick Sengi are two furry friends on hand to guide you through the book and break down the basics. They’ll give you the lowdown on levers, pulleys, screws, inclined planes, wedges, and wheels on this intrepid adventure. You’ll find out how all different technologies work, from bicycles, cranes, and drills to diggers, hammers, and zips. Along the way, you’ll help Sloth and Sengi plot their daring escape from the zoo using only newfound scientific knowledge to make a machine designed for break outs and break aways. But will they succeed? Grab this essential guide, get your brain in gear, and get set for engineering greatness.