Pliny is already a famous scholar. He visits Hero in Alexandria bringing engineers with him. Hero's aeolipile is demonstrated. Roman engineers are delighted and do some experiments, one of them accidentally sealing the steam vents. The toy explodes, injuring the engineer but demonstrating the power of steam. January 10, 45CE Indus January 10, 47CE Rome April 5, 50CE Athens The Greek Philosopher Caltrix takes the first steps on the way to the decimal system after a visit to India . To demonstrate the power of his tool he calculates the number of water drops in all the oceans. August 5, 55CE Rome