The Chinese devise a sign for zero. In 1202 it is introduced to Europe for the first time, where it begins to change the way people do maths.

Jordanus Nemorarius writes the book Mechanica which contains a law about the way levers work and a law on the composition of movements.

The earliest known description of a wheelbarrow appears as a stained glass window in Chartres Cathedral in France.

The alchemist Arnold of Villanova ALMOST discovers carbon monoxide and is the first known person to prepare pure alcohol.

The Chinese use bombs to produce shrapnel and damage - until then explosives had only been used to produce fire, light, noise and confusion among the enemy. They also use kites as a way of sending signals behind the enemy lines.

In 1270 Witelo publishes his Perspectiva, a book on optics which deals with refraction, reflection and geometrical optics. Perhaps most importantly, Witelo rejects the current idea that rays of light are emitted from the eye.

The Chinese make the first guns, which are in fact small cannons.

Astronomy becomes more accurate - William of St Cloud measures the angle of the eliptic of the Sun as 23 degrees 34 minutes. This is only 2 minutes away from the value accepted as accurate at the beginning of the 21st century.

In 1284, Al-Quarashi (also known as Ibn al-Nafis) works out the correct anatomy of the heart and the way in which the blood flows through it.

Giles of Rome publishes a book explaining how the body forms in the uterus, and the role of both parents in the process.