Ancient World

Martha Washington- the very first lady of the United States

When you here Paris, it is the capital city of France but you didn’t know it had a mystery.

The first Stethoscope invented in 1816 by a French inventor Rene Laennec.

The first book written by Sir Isaac Newton in 1687.

Oxygen was one of the early experiments on combustion of air conducted during the 2nd Century BC in Greece. It was first done by a writer on mechanics, Philo of Byzantium. In his work Pneumatica, he observed that inverting a vessel over a burning candle and surrounding the vessel's neck with water resulted to some water rising into the neck.
Many centuries ago, an Italian scientist Leonardo da Vinci constructed Philo's work when he observed a portion of air consumed in the combustion and respiration.
Air was necessary in combustion when it was proved by Robert Boyle during the late 17th century. English chemist John Mayow refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus.
As time goes by, an English chemist Joseph Priestley made his own experiments which he did in 1774. He prepared oxygen by heating mercury oxide through a burning glass. Many scientists made more experiments about oxygen until it was named by a French chemist, Antoine Lavoisier.

This is one of the ships of the Portugeuse explorer Ferdinand Magellan in his voyage of circumnavigation during the early 16th century.