As early as 300 years before our era, a wooden wheel with pegs inserted into its circumference was the first cogwheel to be used in ancient Egyptian horse mills, called "Göpel". These mills were large turning devices for driving working machines, which were moved by people or animals walking in circles.
A further development later led to the invention of the well-known pulley block. The first confirmed tradition about the use of cogwheels refers to a cog-wheeled water clock from 250 BC. The most important artefact for the use of cogwheels in antiquity is the mechanism of Antikythera from around 100 BC.
From the 9th century onwards, cogwheels were used in water mills, and from the 12th century onwards they were also used in windmills. It took more than half a millennium until Da Vinci, around 1500, used gears for his numerous inventions. For a long time, little attention was paid to the shape of the cogwheel itself.
It is assumed that the Danish astronomer Ole Rømer used the epicycloidal tooth form when building his planetariums. This tooth shape ensured for the first time a uniform movement and thus a more secure gait. Mathematicians proved this and so these gears were also used in clockworks for the first time after 1730.
Would you have known it?