The history of the steam engine stretches back as far as the 1st century AD; the first recorded rudimentary steam engine being the aeolipile described by Hero of Alexandria. Over a millennium after Hero's (or "Heron's") experiments, a number of steam-powered devices were experimented with or proposed, but it was not until 1712 that a commercially successful steam engine was finally developed, Thomas Newcomen's atmospheric engine. During the industrial revolution, steam engines became the dominant source of power and remained so into the early decades of the 20th century, when advances in the design of the electric motor and the internal combustion engine resulted in the rapid replacement of the steam engine by these technologies. However, the steam turbine, an alternative form of steam engine, has become the most common method by which electrical power generators are driven. Investigations are being made into the practicalities of reviving the reciprocating steam engine as the basis for a new wave of 'advanced steam technology' .