European Jesuit visitors to China like Matteo Ricci and Nicolas Trigault briefly wrote about Chinese clocks with wheel drives, but others mistakenly believed that the Chinese had never advanced beyond the stage of the clepsydra, incense clock, and sundial. They thought that advanced mechanical clockworks were new to China and that these mechanisms were something valuable that Europeans could offer to the Chinese. Although not as prominent as in the Song period, contemporary Chinese texts of the Ming Dynasty (1368–1644) described a relatively unbroken history of mechanical clocks in China, from the 13th century to the 16th. However, Su Song's clock tower still relied on the use of a waterwheel to power it, and was thus not fully mechanical like late medieval European clocks.