Although rockets may have seem to be a very new invention, they are in fact very old. Not of course the type of rocket which takes people into space, but the sort we regard today as a firework. This type of rocket was known to the Chinese over thousand years ago!

Every gallon of sea water has about four ounces of salt in it, on average. This means that if you dried the sea out to obtain the salt in it, there would be enough salt to put a layer of the chemical around the world 147 feet thick!

Each autumn the cubs born to a pair of wolves join their parents in hunting as family group. A typical wolf-pack like this may have five members, but if the winter is particularly hard, family packs join up to form a larger pack. A large wolf-pack join up to form a larger pack. A large wolf pack rarely has more …

If you look up into a clear night sky in the heart of country well away from town light, you will be able to see about 2,000 stars. In the entire sky, there are between 5,000 and 6,000 stars visible to the naked eye. But there are millions upon millions of stars to be seen through a powerful telescope.

People grow two sets of teeth during their lifetimes the primary or baby teeth, and the second, permanent teeth. The first primary teeth appear when a child is about six months old. The rest of them erupt between sixth and thirtieth month, and there are only twenty teeth in this set. The permanent teeth in humans appear between the sixth and …

As many as eight people can fly aboard the space shuttle. One of them is the commander and another the pilot who flies the shuttle. The other members of the crew are called mission specialists and payload specialists. They operate the equipment taken into space by the shuttle.

There are two kinds of spring. One are called “Permanent Springs” and others “Intermittent Springs”. The water in Permanent Springs flow throughout the year. They get water from a deep point of water zone. In “Intermittent Springs” water flows generally in rainy season because the level of the water table is highest during that period. The openings of such springs …

A good question! We know that there are about one million different species of insect, but more are being discovered every day. Except for the sea, every place on earth has an insect population, and some of these insects are very useful indeed. The honey bee and butterflies are two the most useful, carrying pollen from one plant to another …

There are many kinds of clouds. They are always changing their shape. They are formed at different heights. There is different temperature at different heights. The clouds are formed according to the height of the moisture laden air. Clouds which are formed at the height of thirty to fifty miles are called ‘noctilucent’ clouds. After these highest clouds, there are …

The number varies because some people have much thicker hair strands than others but the average number is 144,000.