Like many scientists who lived 300 years ago, Benjamin Franklin worked on lots of different problems in science. But it wasn’t enough for him to just understand the science. With each discovery he made an invention: something to make people’s lives easier and safer. He made no money from his inventions, believing that they should be used freely by everyone.

Benjamin Franklin was scientist and diplomat. He was important in the American War of Independence, securing French support and thus effectively ending the war. He studied electricity, light, music and many other scientific subjects. Having spent some time in Britain he was in close contact with some famous British scientists, and worked with them on some of the major scientific problems of the time.

Benjamin Franklin is most famous for his work on electricity.

Question 1
He proved that lightning was electricity by doing what dangerous activity during a thunderstorm?
Flying a kite

Franklin apparently tied a metal key to a kite and flew it in a thunder storm. The key and kite conducted electricity which helped him prove that lightning was electricity. Lightning tends to strike the tallest object around, so flying a kite with a key attached to it was a very dangerous thing to do!

Question 2
What did he invent, following what he had learnt in this experiment?
A lightning rod

If you look carefully then you can usually see lightning rods on tall buildings today - they are a little spike which is higher than any other part of the building. Leading from this spike is a thick metal wire which runs down to the ground and helps stop the building from getting damaged if struck by lightning.

Question 3
Electricity flows through conductors. Which of these materials is a good conductor and could have been used to make this invention?

Electricity will travel more easily through metal than through glass or wood which makes it the perfect material for a lightning rod.

Question 4
Towards the end of his life Benjamin Franklin needed glasses for seeing long distances and for reading. He invented a pair that would do both. What do we call these?

If you look at the word 'Bifocal' then you might be able to work out what it means. 'Bi' means two, and 'Focal' is related to the word 'focus'. So you can focus on things that are both close to you, and things that are far away with a pair of bifocals.

Question 5
When he was postmaster in Philadelphia in 1775, Benjamin Franklin had to work out the fastest route for delivering mail. He did this by inventing an odometer. What does an odometer measure?
The distance travelled

By working out the distance travelled, Franklin could work out what the shortest (and possibly the fastest) route was.

Question 6
Benjamin Franklin invented the Franklin stove, a wood burning fireplace which was safer than a normal open fire. Apart from its safety, what made it so popular?
It was more efficient, giving out more heat while burning less wood.

It was more efficient which meant that people didn't need to buy as much wood and they could spend their money on other (possibly more exciting) things!

Question 7
While travelling from America to Britain he studied the Gulf Stream, a warm current which flows like a giant river across the ocean. Which ocean?
The Atlantic Ocean

The Pacific Ocean lies between the Americas and Asia, and the Indian Ocean lies between Africa and Australia.

Question 8
Benjamin Franklin noticed that wearing wet clothes on a warm day makes you cooler, because the water carries off heat as the clothes dry. When liquid water turns into a gas - water vapour - what is this called?

Evaporation is also the reason that you feel chilly when you first get out the bath. All the little droplets of water left on your skin are evaporating taking the heat away - so best to get dry as soon as you can!

Question 9
One of Benjamin Franklin's first inventions was swim fins, which went on a swimmer's hands. Which animal might have inspired this invention?
A frog

A frog has webbed feet which helps it move through the water when it is swimming. Today divers use flippers on their feet to do the same thing.

Question 10
While living in London Franklin invented his 'armonica', a musical instrument. What type of material made the sound?

Find out how to make your own glass armonica with our Unusual Instruments activity.

Curriculum Links


Working scientifically


Lower key stage 2 Year 3


Lower Key stage 2  Year 4
States of matter


Upper key stage 2 Year 5
Properties and changes of materials


Upper key stage 2 Year 6

Numeracy: Measurement

Reading - Comprehension


Locational knowledge


Develop an understanding of the history of music

Scottish Curriculum

Literacy and English


LIT 2-16a

Reading - Understanding, analysing and evaluating

Social Studies

SOC 2-06a

People, past events and societies

Benjamin Franklin

Benjamin Franklin was born in America in 1706. He lived in London for many years and worked with some of the most famous scientists of that time. He lived to be an old man, and during his life there were many changes in how people lived and worked. Benjamin Franklin was an inventor. He found solutions for many problems and he didn't patent his inventions, believing that knowledge should be shared for free.

As well as being a scientist and inventor, Benjamin Franklin was a diplomat. When America and Britain declared war, he helped end it by getting the French to side with the Americans. In 1783 America won and the United States of America was free from British rule.


Can you work out what Benjamin Franklin did?

Benjamin Franklin is most famous for his work on electricity, but can you work out what else he invented?

Take the quiz online here,

or download the pdf worksheet.