Resumen
Resumen de La filosofía de Rollo: el aire
Para quién es
Readers who like to see science worked out with bellows, lamps, umbrellas and boats, and parents or teachers who want a warm family tale that explains how air, fire, wind and sound behave.
De qué trata este libro
Rollo's Philosophy: Air is a book of science for children by Jacob Abbott, the American author who wrote a whole series of Rollo books in the nineteenth century. Its aim is to teach how air behaves by wrapping each lesson in an ordinary day on a family farm. Rollo, his little brother Nathan, their cousin James, the hired man Jonas and the boys' mother and father work through one small adventure after another, and each chapter closes with questions to test what you have taken in.
In about nine minutes you get the whole course. You learn why a boy cannot fly with borrowed wings, why a bellows blows, how the weight of the sky presses on everything, why warm air rises, what a fire needs to live, and how wind and sound travel. Every idea comes with the scene that makes it plain. The first scene begins with a sled trip across the snow.
En este resumen
- 1Flying takes strength, and air is realFree
- 2A bellows proves air is a real thing
- 3We live at the bottom of an ocean of air
- 4Warm air rises when cool air pushes under
- 5A fire needs fresh air to live
- 6Gravity, wind and sound all move air
Idea clave 1 de 6
Flying takes strength, and air is real
The book opens with a walk across crusted snow, where Rollo, Lucy and Nathan lose their way in a snowfall. That evening Nathan reads his father a rhyme about fins and wings and announces that he wishes he could fly. His father answers that the trouble is not a lack of wings. The trouble is a lack of the strength to work them. Making wings would be easy for clever mechanics, he says, because finding the power is the hard part of almost every machine.
Mr. Holiday then separates two kinds of strength. A boy is absolutely stronger than a robin, since he can hold it and lift more than it can. He is not relatively stronger, because he is not stronger by as many times as he is bigger. To make the point, he asks the boys to imagine climbing a ladder hand over hand while the ladder sinks under their weight. That is the bird's task, pulling itself up on air that keeps giving way.
So a bird needs either huge wings and great force or small wings that beat very fast. Sparrows beat too quickly to count, and hummingbirds make a hum. Rollo and Nathan flap their arms, but their father points out that a crow's spread wings are two or three times as long as its body. Birds can also throw themselves forward and then glide on the speed they have gathered, like swallows circling with still wings. People cannot simply paddle through air as they do through water, because water holds them up and air is usually moving fast.
The father also explains why solid things fall. Nothing visible is lighter than air, and he calls that lucky, since loose things would otherwise float up and shut out the sun. Things spread wide, such as feathers, soap bubbles and umbrellas, fall slowly because they drag a mass of air down with them. That is the idea of the parachute. Rollo tests it by jumping off the shed with his father's umbrella and lands hard, because a true parachute is far larger.
That’s 1 of 6 key points.
The rest of the summary, written and spoken, and the whole book: free to start.
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Questions about La filosofía de Rollo: el aire
What is Rollo's Philosophy: Air about?
It is a teaching book in which Rollo, his brother Nathan, cousin James, Jonas and their parents learn how air works. Flight, bellows, pressure, balloons, chimneys, fire, gravity, wind and sound are each explained through a small scene.
Who are Rollo, Nathan and Jonas?
Rollo is the older boy who loves experiments and sometimes shows off. Nathan is his little brother, full of questions. Jonas is the thoughtful hired man who knows the workshop, the fire and the weather, and teaches by doing.
What does philosophy mean in the title?
In Abbott's day, philosophy meant the study of how nature works, what we now call science. The title promises a lesson in the science of air, taught by experiments the children can try with ordinary things.
Is Rollo's Philosophy: Air easy to follow?
Yes, because the lessons come as conversations and short adventures. A friendly father, a patient mother and a helpful workman explain each idea in plain words, and questions at each chapter's end help you review it.
What are the main lessons of the book?
Air is a real substance with weight. It presses, springs back when squeezed, rises when warmed and feeds fire. Wind and sound are forms of its motion. Careful experiments, and a calm mind about mistakes, show you what is true.