Hero of Alexandria

Hero of Alexandria, also called Heron, was a Greek mathematician and engineer who worked in Alexandria under Roman rule, probably in the first or second century AD. He is described as one of the greatest experimentalists of antiquity and belongs to the Hellenistic scientific tradition. His best known device is the aeolipile, a steam-powered apparatus often called Hero's engine, and he also described a windwheel, which is the earliest recorded use of wind power on land. In his Mechanics he treated pantographs, and some of his ideas build on the work of Ctesibius. In mathematics he wrote a commentary on Euclid's Elements and the applied geometry text Metrica, and he is remembered for Heron's formula for the area of a triangle from its three side lengths. Much of his original writing and design work is lost; what survives came down through Byzantine manuscripts and, less fully, through Latin and Arabic translations.