1. To get a constant current, you must have its source. 2. A pyrometer is used to measure the temperature of hot metals. 3. Man learned to dissolve atoms in order to receive a large amount of energy. 4. Scientists are trying to solve the problem associated with new phenomena of electricity. 5. Lightning rod-metal device for protecting buildings from lightning. 6. Carrying out experiments with atmospheric electricity was very dangerous at that time. 7. To magnetize an object is to place it in a magnet field.
Now I want to give a talk about similar huge stones in Russia - Dolmens.
We can see them on Caucasus. They look like small houses of three monolithic stones. They are really heavy and nobody knows how people moved and lifted them. Last year some scientists tried to move the Dolmen to the other place. But they have failed it. The Dolmen just crashed to it's 3 stones.
Nobody knows who build it and when. Nowadays people use Dolmens like tourists attraction. They drive them to the place and tell them some stories about Dolmens.
That's all I wanted to say.