to add papermaking to the three major inventions mentioned above, and in comparing Japan and China he noted that "we must always remember that they (meaning Japan) have no such remarkable inventions as printing, papermaking, the compass, and gunpowder." Papermaking Papermaking has traditionally been traced to China about AD 105, when Cai Lun, an official attached to the imperial court during the Han dynasty (202 BC – AD 220), created a sheet of paper using mulberry and other bast fibres along with fishing net, old rags, and hemp waste. However, a recent archaeological discovery has been reported from Gansu of paper with Chinese characters on it dating to 8 BC. While paper used for wrapping and padding was used in China since the 2nd century BC, paper used as a writing medium only became widespread by the 3rd century. By the 6th century in China, sheets of paper were beginning to be used for toilet paper as well. During the Tang dynasty (618–907) paper was folded and sewn into square bags to preserve the flavor of tea. The Song dynasty (960–1279) that followed was the first government to issue paper currency. Before paper was invented, the ancient Chinese carved characters on pottery, animal bones and stones, cast them on bronzes, or wrote them on bamboo or wooden strips and silk fabric. These materials, however, were either too heavy or too expensive for widespread use. The invention and use of paper brought about a revolution in writing materials, paving the way for the invention of printing technology in the years to come. Compass The compass in the Four Great Inventions was formerly the compass of ancient China. It is a kind of direction-indicating tool, which is widely used in navigation, field exploration and other fields. In ancient times, it had a profound influence on trade, war and cultural exchange. The compass's origins may be traced back to the Warring States period (476–221 BC), when Chinese people utilized a device known as a si nan to point in the right direction. During the early Song dynasty, a spherical compass with a small needle made of magnetic steel was created after steady development. The little needle has one end pointing south and the other pointing north. During the Northern Song dynasty (960–1127), the compass was brought to the Arab world and Europe. People relied on interpreting the positions of the sun, moon, and