The Thread That Glowed
You flip a switch, and the room fills with light. Who made the light bulb?
Thomas Edison is the name most people know. But he did not make the very first bulb.
Other people made bulbs before he was born. Their bulbs burned out in a few minutes.
Edison made the first bulb that was practical. It lasted for hours and hours.
Edison's mom taught him at home. He learned by reading and trying things.
He had a small lab in his cellar. Later he built a bigger lab in Menlo Park.
Edison did not work alone. He called his helpers muckers. He picked teams of them to build each new thing.
A bulb needs a thin thread that glows inside it. That thread is called a filament.
One helper tried thousands of things for the filament. He tried platinum and rubber. He even tried soot from lamps.
Then the team tried a cotton thread. They baked it until it was black and hard. They sealed it in glass with the air pumped out.
The thread glowed! It glowed for at least thirteen hours. The team had a bulb that lasted.
Later a helper found something better. It was bamboo from Japan. A bamboo thread glowed for a very long time.
A bulb is not enough. The team also made switches, meters, and wires. Without a wire, the bulb could not glow.
In 1882, a power station sent light down wires. It lit just a small part of New York. Many years later, half of all homes had electricity.
Look at a light bulb at home. Do not touch it, because it can be hot. Can you see a tiny thread inside?
That thread is a filament. What do you think the team said when it glowed?
Questions
- Yes, he made the first one
- No, others made bulbs before him
- No, he never made a bulb
- It glowed for hours
- It was very big
- It was red
- A switch on the wall
- A tiny thread that glows inside a bulb
- A kind of lamp oil
- A cotton thread
- A glass bulb
- A wire
- Very old
- Useful in everyday life
- Very pretty
- They were bored
- Because a bulb needs them to work in a home
- The bamboo broke
Words to know
- filament: glowing thread
- muckers: lab helpers
- practical: useful in life
- bamboo: tall woody grass
- lab: science workroom
Answer key: The Thread That Glowed
- B. No, others made bulbs before him
- A. It glowed for hours
- B. A tiny thread that glows inside a bulb
- A. A cotton thread
- B. Useful in everyday life
- B. Because a bulb needs them to work in a home
Teaching a mixed class? The light bulb at three reading levels
Three true passages from the same facts, a basic, a middle and an advanced one, so every group reads about the same thing and the class can talk about it together. Print one PDF: a sheet for each group, marked with a shape instead of a level, and a page for you that says which is which.
- ● The Thread That Glowed (this passage)Basic, for about 6 to 8 · reading level 7 · 297 words · Flesch-Kincaid grade 2 · 6 questions
- ▲ Who Invented the Light Bulb?Middle, for about 9 to 12 · reading level 11 · 844 words · Flesch-Kincaid grade 6 · 6 questions
- ■ A Practical Lamp, Not a First OneAdvanced, for about 13 to 16 · reading level 14 · 1267 words · Flesch-Kincaid grade 8.7 · 6 questions
The story in pictures
- Part One · Who Made It?
- Part Two · The Search
- Part Three · The Whole Idea
For the teacher: how this passage is levelled
“The Thread That Glowed” is a reading level 7 story. Every Peabody story at this level is written and checked to keep sentences to 10 words or fewer, to aim at an average of 6 words a sentence, and to show 12 to 30 words on a screen. At most 8% of its words may be off the familiar-word list. Children in 3rd grade start at this level.
| This passage | 297 words, 16 screens, 6 multiple-choice questions with an answer key, and 5 vocabulary words with kid-sized meanings |
|---|---|
| Longest sentence at this level | 10 words |
| Words on a screen | 12 to 30 |
| Skills practised at this level | phonics (sounding words out), sight words, spelling |
Reading level 7: the limits, a real sample and the free games. Peabody is a learning app, not an assessment: use the questions to talk about the story, not to grade a child.