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HISTORY OF MARINE ARCHITECTURE.

‘ The nature and cause of the qualities of the magnet have, at all times,, beensubjects of co itemplation among the Chinese. Their theory, in this instance, asin many others, is the reverse of that of European philosophers. It is obvious,that while the magnetic needle, suspended by its centre, points at one extremityto the north, it necessarily looks, at the other, to the south ; but eacli retains itsown polarity; and if turned round by force, will resume, when left at liberty,its original station, opposite to its respective pole. Thus the power, which prin-cipally attracts the needle, may be supposed to reside toward either, or both por-tions of the earth. In Europe it has been thought that the needle has its chieftendency to the north pole ; but, in China, the south alone is considered as con-taining the attractive power. The Chinese name of the compass is ting-na7i-chmg,or needle pointing to the south ; and a distinguishing mark is fixed on the mag-net’s southern pole, as it is in European compasses upon that of the north.

‘ The Emperor, Caung-Shee, grandfather to the present, who was in the habitof committing to paper his observations upon a variety of subjects, and who,having encouraged learned missionaries at his court, had not been inattentive totheir philosophical opinions, writes on this occasion, ** I have heard Europeanssay, that the needle obeys the north. In our oldest records it is said, it turns tothe south ; but as neither have explained the cause, I see but little to be gained inadopting one opinion in preference to the other. The ancients, however, arefirst in date ; and the farther I proceed, the more I am convinced of their know-ledge of the operations and mechanism of nature. Moreover, as all action growslanguid, and nearly is suspended towards the north, it is less likely that the virtuewhich gives motion to the magnetic needle, should proceed from that quarter.”

‘ An allusion is made likewise to this property of the magnet in the books ofChinese mythology, or fabulous portion of the history of the empire. It is thererelated, that in the reign of Chin-Nong, a rebel, of the name of TchooYoo, hadfound, in order the better to elude or confound his enemies, the means of creating,at his pleasure, thick fogs, and even utter darkness; to prevent the effect ofwhich, the emperor invented a machine, consisting of a figure standing in achariot, with one arm stretched out, and pointing always to the southward,which circumstance enabled the imperial troops to follow the proper track fordiscovering and overthrowing the rebel.

‘ The emperor, Caung-Shee, was well aware, however, that the needle doesnot always point directly either to the south or north ; and that this declination isnot the same in all countries, nor invariable in the same place ; but the sphere of

Chinese