Sir Oliver Lodge 131 



copper or iron with a sharp point at the top, and that 

 the lower end is connected with a metal plate buried in 

 damp ground. The object is twofold : first to drain away 

 the electricity from passing clouds and so render them 

 harmless; secondly, when this is impossible, to receive 

 the flash and convey it to earth without harming the 

 building to which the conductor is attached. 



For many years after Franklin first used it the light- 

 ning conductor was not generally adopted, but by the 

 middle of the last century it was used on all church spires, 

 factory chimneys, and similar tall buildings, and it was 

 supposed to afford complete protection. But while con- 

 ductors doubtless saved many lives and buildings, pro- 

 tected buildings were sometimes struck. 



Several of these are mentioned in Sir Oliver's book. 

 There was an instance at a house in Wavertree, where 

 lightning struck a church which had a conductor, and at 

 the same time a gas pipe was melted in an underground 

 cellar of the house opposite, and the gas was fired. On 

 May 14, 1889, Mangalore Lighthouse, off the east coast 

 of Madras Province, in India, was struck, one man being 

 killed and two injured. In this case a spark was actually 

 seen to rise from the floor inside the lighthouse. The 

 man who was killed was standing near a coil of galvanized 

 iron fencing-wire which lay inside the room; this was 

 only five feet from the conductor, though separated from 

 it by the outside wall. 



These and other similar events gave people the idea 

 that lightning conductors were of little use, and then it 

 was that Sir Oliver Lodge began to make a special study 

 of the subject. 



Clerk Maxwell had already pointed out that there is 

 only one perfect protection against lightning, that being 

 to enclose the chamber in a metallic cage or sheath 

 through which no conductor is allowed to pass without 

 being thoroughly connected to it. But of course this 



