when were the first magnetic compasses used by chinese ships
1040–44
title: History of the compass text: the sky was overcast or foggy, and when landmarks were not in sight. This enabled mariners to navigate safely far from land, increasing sea trade, and contributing to the Age of Discovery. The compass was invented in China during the Han Dynasty between the 2nd century BC and 1st century AD, where it was called the "south-governor" ("sīnán" ). The magnetic compass was not, at first, used for navigation, but for geomancy and fortune-telling by the Chinese. The earliest Chinese magnetic compasses were possibly used to order and harmonize buildings in accordance with the geomantic principles of "feng shui". These title: History of the compass text: History of the compass The compass was invented more than 2,000 years ago. The first compasses were made of lodestone, a naturally magnetized ore of iron, in Han dynasty China between 300 and 200 BC. The compass was later used for navigation by the Song Dynasty. Later compasses were made of iron needles, magnetized by striking them with a lodestone. Dry compasses begin appearing around 1300 in Medieval Europe and the Medieval Islamic world. This was replaced in the early 20th century by the liquid-filled magnetic compass. Prior to the introduction of the compass, geographical position and direction at sea title: Compass text: south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearings, which are commonly stated in this notation. Among the Four Great Inventions, the magnetic compass was first invented as a device for divination as early as the Chinese Han Dynasty (since c. 206 BC), and later adopted for navigation by the Song Dynasty Chinese during the 11th century. The first usage of a compass recorded in Western Europe and the Islamic world occurred around 1190. The magnetic compass is the most familiar compass type. It functions as a pointer to "magnetic north", the title: Chinese exploration text: History of the Song Dynasty, and Islam during the Song Dynasty." In China, the invention of the stern-mounted rudder appeared as early as the 1st century AD, allowing for better steering than using the power of oarsmen. The Cao Wei Kingdom engineer and inventor Ma Jun (c. 200–265 AD) built the first south-pointing chariot, a complex mechanical device that incorporated a differential gear in order to navigate on land, and (as one 6th century text alludes) by sea as well. Much later the Chinese polymath scientist Shen Kuo (1031–1095 AD) was the first to describe the magnetic needle-compass, along with title: History of the compass text: China. However, some scholars proposed an independent European invention of the compass: There is disagreement as to exactly when the compass was invented. These are noteworthy Chinese literary references in evidence for its antiquity: Thus, the use of a magnetic compass by the military for land navigation occurred sometime before 1044, but incontestable evidence for the use of the compass as a maritime navigational device did not appear until 1117. The typical Chinese navigational compass was in the form of a magnetic needle floating in a bowl of water. According to Needham, the Chinese in the Song Dynasty and continuing