Why are sewer manhole covers round?
A familiar detail of the urban landscape is sewer manhole covers, almost everywhere, in all countries of the...
Where do alpacas live?
One of the major export items of Peru is the excellent wool, which is valued all over the...
Why do animals need a tail?
Many animals can boast of having a tail: animals and birds, amphibians, and fish. But we will tell...
How much hair should a person lose per day?
If one day, after combing your hair, you notice that there are suspiciously many hairs left on the...
What is a barometer and what is it for?
There are many ways to get information about the world. You can, for example, just look out your...
What is a hygrometer and what is it for?
The most important indicators that determine environmental conditions are temperature and humidity. Every household today has a thermometer...
What is an echo sounder and how does it work?
A modern sea or river vessel cannot do without navigational instruments, one of which is a sonar. With...
What is an anemometer, and what does it measure?
Almost everyone has heard of the anemometer. The device is actively used in meteorological stations and is indispensable...
What is a heliograph? Why do I need it?
The word “heliograph” means “writing the sun” in Greek. Currently, there are two types of instruments bearing this...
What is a compass and what is it for?
The compass is one of the greatest inventions of humanity, a device for orientation. Its appearance is comparable...