by Susan Silverman AC Page 2HOW I MADE THIS MODEL I had a lot of trouble locating a piece of magnetite large enough to make a spoon. I also learned from people who worked with stone that magnetite is extremely difficult to work. It is all the more amazing that the Chinese were able to work with such a stone. Consequently to make this model, I decided to use sheet steel, heated and hammered to form a spoon shape. A handle was welded on and then tapered to create a balance point (many thanks to Trash Can Forge and Scott Cunningham of Hancock, NH) . It was then magnetized with a device at the Smith Physics lab. The plate and strips were cut from a sheet of brass, then the symbols were painted on the surface with nailpolish (many thanks to Xiaoching Chi). The plate was then etched in acid to make the characters stand out. The whole was assembled and sprayed with lacquer to keep the brass from tarnishing. It was difficult to achieve a sufficient magnetic strength to overcome the friction of the plate, thus the device has some limitations as a compass.SOURCE: Needham, Joseph, Science and Civilization in China, Vol. 4, part 1:Physics, Cambridge Univ. Press, 1962. No worries! We‘ve got your back. Try BYJU‘S free classes today! No worries! We‘ve got your back. Try BYJU‘S free classes today! Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses No worries! We‘ve got your back. Try BYJU‘S free classes today! Open in App Suggest Corrections 0 By the 1300s, magnetic compasses were being used across Europe and the Middle East. Although some historians contend that the Europeans independently created magnetic compasses from iron ore several centuries after the Chinese, most believe that the Chinese introduced their compass to the Muslims, who then shared the knowledge with Europeans. Alexander Neckam’s work De Naturis Rerum, or On the Nature of Things, which was written in 1190, mentions that sailors from the East use magnetized needles to guide them, the first textual reference in Europe of the use of compasses. |