532 THE INTELLECTUAL RISE IN ELECTRICITY. 



There was an ornamental octagonal pond in the Tuiler- 

 ies gardens of those days, which measured about an acre 

 in extent. Around the semi-circumference of this Le 

 Monnier disposed an iron chain so that its ends came 

 diametrically opposite one another. These ends were 

 held respectively by two observers, one of whom dipped 

 his disengaged hand in the water. The other, across the 

 basin, held in his free hand an electrified Leyden jar, the 

 inserted wire of which he thus presented to an iron rod 

 which entered the water, and was supported on a cork 

 float. Thus early in 1746, a circuit was made including 

 both water and a metallic conductor, over which passed 

 the discharge of the jar, so that the two observers were 

 simultaneously shocked. 



Like other experimenters who had dealt with long 

 conductors, Le Monnier sought to measure the velocity 

 with which the electric matter ran over them, but without 

 avail; nor was he any more successful in finding out what 

 impelled it at a speed which he estimates to be at least 

 1 4 thirty times that of the velocity of sound in air." He 

 made up his mind, however, that the electric matter is 

 communicated to bodies in proportion to their surfaces, 

 and not in proportion to their masses. 



The conclusions of Le Monnier appear to have been re- 

 garded by the English electricians as a challenge. Wat- 

 son was now their leader, and his response was ready. Le 

 Monnier had dealt with the jar as a mere electrified mass, 

 operating to increase the shock or spark, for some reason, 

 unknown. Watson, 1 in reply, declares that it owes its 

 capabilities to the accumulation of electrical matter within 

 it this happening because the glass acts as a barrier and 

 prevents the electrical matter escaping from the water as 

 it is supplied thereto by the inserted wire. We shall see 

 changes in these notions soon. Meanwhile, as for the rest 

 of Le Monnier's observations, they merely prove, says Wat 



1 Phil. Trans., No 482, p. 388. Watson: Exp'ts. and Obs'ns. on Elec'y. 

 3d ed. London, 1746. 



