What is pointillism? Pointillism is a technique in painting. It uses small dots of pure colour to build up images. If one views these images from a distance, they seem to blend together and produce a wide range of colours and tones. Georges Seurat and...
Why do our eyes tear when we cut onions? When we cut onions, a chemical is released into the air. This reacts with moisture on the surface of our eyes forming a weak solution of sulphuric acid. The acid induces a stinging sensation. The eyes...
How are underground railways built? Under the cities lie the foundations of large buildings and many pipes which transport water, gas electricity and telephone cables. Underground railway builders have two options. They can either dig deep tunnels or they can run the railway under the...
What is yellow fever? Yellow fever is caused by a virus which attacks the liver. Symptoms include fever, jaundice and vomiting. Damage to the liver cells causes jaundice which gives the skin a yellow colour and hence the name. The virus is spread by mosquitoes....
Who carved the faces on Mount Rushmore? The Mount Rushmore National Memorial honours four American presidents George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt. It was an American sculptor, Gutzon Borglum, who etched the likenesses of the four men into the granite. The work...
Why are port and starboard so called? The port is the left side of a ship, looking forward. The right side is called the starboard side. Starboard comes from the word ‘steerboard’. Early ships were steered by a large oar found usually on the right...
What kind of people were the Celts? The Celts, both men and women, were great warriors. They would paint their faces and bodies blue for a fierce look. There were frequent fights between tribes. Some fighters did battle naked but others wore tartan tops, capes...
Why does the chameleon change colours? Animals use the technique of camouflage to escape predators. By changing colours the chameleon is camouflaging itself. This is made possible thanks to special red, black and yellow cells in its skin. The chameleon changes colours by changing the...
How do telephones work? Telephones work by sending and receiving electrical signals which represent sounds. When we dial a number a signal passes to another telephone which makes it ring. When the telephone is picked up, a connection is made and people can talk to...
What is the difference between toadstools and mushrooms? There are no differences between the two. In scientific terms there is nothing called a toadstool. Some people call poisonous mushrooms toadstools. But botanists do not use the term. Mushrooms are actually fungi. Poisonous mushrooms contain a...
