194 Things not generally Known. 



to commercial purposes, as so many do, we should not like to set a limit 

 to his professional income. The quality of his services cannot be ex- 

 pressed by pounds ; but that brave body, which for forty years has been 

 the instrument of that great soul, is a fit object for a nation's care, as 

 the achievements of the man are, or will one day be, the object of a 

 nation's pride and gratitude. 



THE CHINESE AND THE MAGNETIC NEEDLE. 



More than a thousand years before our era, a people living 

 in the extremest eastern portions of Asia had magnetic carri- 

 ages, on which the movable arm of the figure of a man con- 

 tinually pointed to the south, as a guide by which to find the 

 way across the boundless grass-plains of Tartary ; nay, even in 

 the third century of our era, therefore at least 700 years be- 

 fore the use of the mariner's compass in European seas, Chinese 

 vessels navigated the Indian Ocean under the direction of 

 Magnetic Needles pointing to the south. 



Now the Western nations, the Greeks and the Romans, knew that 

 magnetism could be communicated to iron, and that that metal would 

 retain it for a length of time. The great discovery of the terrestrial 

 directive force depended, therefore, alone on this that no one in the 

 West had happened to observe an elongated fragment of magnetic iron- 

 stone, or a magnetic iron rod, floating by the aid of a piece of wood in 

 water, or suspended in the air by a thread, in such a position as to ad- 

 mit of free motion. Humboldts Cosmos, vol. i. 



KIECHEE'S " MAGNETISM." 



More than two centuries since, Athanasius Kircher pub- 

 lished his strange book on Magnetism, in which he anticipated 

 the supposed virtue of magnetic traction in the curative art, 

 and advocated the magnetism of the sun and moon, of the 

 divining-rod, and showed his firm belief in animal magnetism. 

 "In speaking of the vegetable world," says Mr. Hunt, "and 

 the remarkable processes by which the leaf, the flower, and the 

 fruit are produced, this sage brings forward the fact of the 

 diamagnetic (repelled by the magnet) character of the plant 

 which was in 1852 rediscovered; and he refers the motions of 

 the sunflower, the closing of the convolvulus, and the direc- 

 tions of the spiral formed by the twining plants, to this parti- 

 cular influence."* Nor were Kircher's anticipations random 

 guesses, but the result of deductions from experiment and ob- 

 servation ; and the universality of magnetism is now almost 

 recognised by philosophers. 



MINUTE MEASUREMENT OF TIME. 



By observing the magnet in the highly-convenient and deli- 

 cate manner introduced by Gauss and Weber, which consists 



* See Mr. Hunt's popular work, The Poetry of Science; or, Studies of Physical 

 Phenomena of Nature. Third editiou, revised and enlarged. Bohn, 1854. 



