Curiosities of Science. 



to the magnet of such a machine, we obtain powerful currents 

 of electricity. If these be conducted through water, the latter 

 will be reduced to its two components, oxygen and hydrogen. 

 By the combustion of hydrogen water is again generated. _ If 

 this combustion takes place, not in atmospheric air, in which 

 oxygen only constitutes a fifth part, but in pure oxygen, and 

 if a bit of chalk be placed in the flame, the chalk will be raised 

 to a white heat, and give us the sun-like Drummond light : at 

 the same time the flame develops a considerable quantity of 

 heat. Now the American inventor proposed to utilise in this 

 way the gases obtained from electrolytic decomposition ; and 

 asserted that by the combustion a sufficient amount of heat 

 was generated to keep a small steam-engine in action, which 

 again drove his magneto-electric machine, decomposed the 

 water, and thus continually prepared its own fuel. This would 

 certainly have been the most splendid of all discoveries, a per- 

 petual motion which, besides the force that kept it going, 

 generated light like the sun, and warmed all around it. The 

 affair, however, failed, as was predicted by those acquainted 

 with the physical investigations which bear upon the subject. 

 Professor Helmholtz. 



MAGNETIC CLOCK AND WATCH. 



In the Museum of the Royal Society are two curiosities of 

 the seventeenth century which are objects of much interest in 

 association with the electric discoveries of our day. These are 

 a Clock, described by the Count Malagatti (who accompanied 

 Cosmo III., Grand Duke of Tuscany, to inspect the Museum 

 in 1669) as more worthy of observation than all the other ob- 

 jects in the cabinet. Its " movements are derived from the 

 vicinity of a loadstone, and it is so adjusted as to discover the 

 distance of countries at sea by the longitude." The analogy 

 between this clock and the electric clock of the present day is 

 very remarkable. Of kindred interest is " Hook's Magnetic 

 Watch," often alluded to in the Royal Society's Journal-book 

 of 1669 as " going slower or faster according to the greater or 

 less distance of the loadstone, and so moving regularly in any 

 posture." 



WHEATSTONE'S ELECTKO-MAGNETIC CLOCK. 

 In this ingenious invention, the object of Professor Wheat- 

 stone was to enable a simple clock to indicate exactly the same 

 time in as many different places, distant from each other, as 

 may be required. A standard clock in an observatory, for ex- 

 ample, would thus keep in order another clock in each apart- 

 ment, and that too with such accuracy, that all of them, how- 

 ever numerous, will beat dead seconds audibly with as great pre- 



