claimed that the first rudderpost recovered was proof of the enormous dimensions of the ships based on his calculations on how big the rudderblade would be. However Church (2010) points out that Zhou was using calculations based on modern steel propeller-driven ships, not wooden ships; as well as the fact that Zhou's hypothetical rudder shape was based on the flat-bottomed shachuan (沙船) ship type, not the sea-going fuchuan (福船). The rudderposts can not be used to infer the actual size of the rudder blades. Church notes that in traditional wooden Chinese ships, rudderposts were necessarily long in order for them to extend from the water level up unto the ship deck, where it was controlled by the tiller. Church compares it with modern wooden junks built in the traditional Lümeimao ("green eyebrow", 綠眉毛) style, which also have rudderposts that are long, but are only in overall length. Death One theory is that Admiral Zheng He died in 1433, during or shortly after the seventh voyage. Another is that Zheng He continued to serve as the defender of Nanjing, dying in 1435. A tomb was built for Zheng He at the southern slope of Cattle Head Hill, Nanjing. The original tomb was a horseshoe-shaped grave. It is a cenotaph believed to contain his clothes and headgear. In 1985, the tomb was rebuilt following a Muslim style. Legacy Zheng's voyages were long neglected in official Chinese histories but have become well known in China and abroad since the publication of Liang Qichao's Biography of Our Homeland's Great Navigator, Zheng He in 1904. Imperial China In the decades after the last voyage, Imperial officials minimized the importance of Zheng He and his expeditions throughout the many regnal and dynastic histories they compiled. The information in the Yongle and Xuande Emperors' official annals was incomplete and even erroneous, and other official publications omitted them completely. Although some have seen that as a conspiracy seeking to eliminate memories of the voyages, it is likely that the records were dispersed throughout several departments and the expeditions, unauthorized by and in fact counter to the injunctions of the dynastic founder, presented a kind of embarrassment to the dynasty. State-sponsored Ming naval efforts declined dramatically after Zheng's voyages. Starting in the early 15th century, China experienced increasing pressure from the surviving Yuan Mongols from the north. The relocation of the capital to Beijing in the north exacerbated this