After the final voyage, the Chinese emperor suddenly ordered that these expensive expeditions be halted. The ships were left to rot in the harbors, and craftsmen forgot how to build such large ships, letting the knowledge slip away.
Mao successfully led a communist revolution and the Communist Party gained power in 1947. They were appealing than the Nationalist Party as they sought preserve 'true' Communist ideology in the country by purging remnants of capitalist and traditional elements. This was supported by the peasants
I do believe the early Egyptians, being as smart as they where used a interesting method of a sundial. It caught the suns shadow and they where able to use it to tell the time.
