One of the greatest secrets of history is the immense contribution of Chinese society to the Western world. Equally interesting, is the failure of some discovery in China to cross over to Western civilization, or even to survive into modern times. For example, a small pox vaccination was used in China in the 10th century, and then 800 years later in the West. However, the practice of modern diagnostic medicine was not widespread in China in more modern times. The mechanical clock was invented in China in the 8th century, and then independently in Europe in 1310. When the Chinese imperial court was shown a mechanical clock by Jesuit missionaries in the 17th century, the scholars were awestruck.

Link:  Marco Polo's father (Niccolo) and uncle (Maffeo) traveled to China before Marco was born.

Link:  Marco Polo

Link:  William of Rubruck

Link:  Ibn Battuta

Link:  John of Plano Carpini