Things not generally Known. 



cision as the standard astronomical time-piece with which they are 

 connected. But, besides this, the subordinate time-pieces thus 

 regulated require none of the mechanism for maintaining or 

 regulating the power. They consist simply of a face, with its 

 second, minute, and hour hands, and a train of wheels which 

 communicate motion from the action of the second-hand to 

 that of the hour-hand, in the same manner as an ordinary clock- 

 train. Nor is this invention confined to observatories and large 

 establishments. The great horologe of St. Paul's might, by a 

 suitable network of wires, or even by the existing metallic 

 pipes of the metropolis, be made to command and regulate all 

 the other steeple-clocks in the city, and even every clock within 

 the precincts of its metallic bounds. As railways and tele- 

 graphs extend from London nearly to the remotest cities and 

 villages, the sensation of time may be transmitted along with 

 the elements of language ; and the great cerebellum of the 

 metropolis may thus constrain by its sympathies, and regulate 

 by its power, the whole nervous system of the empire. 



HOW TO MAKE A COMMON CLOCK ELECTRIC. 



M. Kammerer of Belgium effects this by an addition to any 

 clock whereby it is brought into contact with the two poles of 

 a galvanic battery, the wires from which communicate with a 

 drum moved by the clockwork ; and every fifteen seconds the 

 current is changed, the positive and the negative being trans- 

 mitted alternately. A wire is continued from the drum to the 

 electric clock, the movement of which, through the plate-glass 

 dial, is seen to be two pairs of small straight electro-magnets, 

 each pair having their ends opposite to the other pair, with about 

 half an inch space between. Within this space there hangs a 

 vertical steel bar, suspended from a spindle at the top. The rod 

 has two slight projections on each side parallel to the ends of 

 the wire-coiled magnets. When the electric current comes on 

 the wire from the positive end of the battery (through the 

 drum of the regulator- clock) the positive magnets attract the 

 bar to it, the distance being perhaps the sixteenth of an inch. 

 When, at the end of fifteen seconds, the negative pole operates, 

 repulsion takes effect, and the bar moves to the opposite side. 

 This oscillating bar gives motion to a wheel which turns the 

 minute and hour hands. 



M. Kammerer states, that if the galvanic battery be at- 

 tached to any particular standard clock, any number of clocks, 

 wherever placed, in a city or kingdom, and communicating with 

 this by a wire, will indicate precisely the same time. Such is 

 the precision, that the sounds of three clocks thus beating simul- 

 taneously have been mistaken as proceeding from one clock. 



