Scienceville
Timeless Inventions
Your pencil has no lead in it, and people once rubbed out mistakes with bread! Let's uncover the surprising stories behind everyday inventions.
Did you know?
A pencil 'lead' has no lead at all! It is made of graphite mixed with clay. Long ago, people thought graphite was a kind of lead, and the name stuck. More clay makes a harder, lighter pencil.
Before erasers, people rubbed out pencil marks with bread! In 1770, Edward Nairne picked up a piece of rubber by mistake instead of breadcrumbs, and found that it rubbed out marks very well.
In 1858, Hymen Lipman got the first patent (an official right to an invention) for a pencil with an eraser on top. Later, it was cancelled, because it was just two old things joined together!
Try this: Nature's Ideas Notebook
Inventors often copy nature. Look closely at three things outdoors, such as a leaf, a seed, a feather or a spider web. For each one, write what is special about it. Does it float, stick or stay dry? Then draw an invention it could inspire, like a raincoat that works like a lotus leaf. Give your invention a name!
Go further: The Dog Walk That Gave Us Velcro
In 1941, a Swiss engineer named George de Mestral went for a walk with his dog. When he got home, prickly burrs (seed cases) were stuck to his clothes and his dog's fur. He wondered how they held on so tightly. This gave him the idea for a fastener with tiny hooks and loops. After years of work, he got a patent in 1955. The name Velcro comes from French words for 'velvet' and 'hook'.