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tion of an admirable scientific method, let us glance at the 

 steps of Franklin's research. First, his attention was taken 

 with the marvels of the rubbed glass tube. These were en- 

 hanced by the storage properties of the Leyden jar. With 

 three friends who had the same infection, he formed a coterie 

 for mutual suggestions and encouragement. They constructed 

 their own machines and with them made new demonstrations 

 of attraction and repulsion, and of the power of electricity to 

 produce light, heat, mechanical violence, nervous shock, and 

 even death. The brilliancy of these experiments depended 

 mainly on Franklin's discovery that the electricity of the Ley- 

 den jar was stored up on the glass, and that by increasing the 

 extent of excited surface the energy was proportionately mul- 

 tiplied. The power thus obtained made it appear highly 

 probable that the difference between the spark and the light- 

 ning flash was one of degree. Having discovered the property 

 of pointed conductors to cause a silent and harmless discharge 

 he next charged an artificial thunder-cloud made of Leyden 

 jars, and with a small pointed rod conducted away its energy 

 without noise or violence. From the truth thus established, 

 he deduced the conjecture that sharp metallic rods fixed at the 

 highest point of buildings would draw away quietly the charge 

 of an approaching thunder-storm. A similar contrivance 

 brought the atmospheric electricity within the reach of his 

 experiments, and its identity with frictional electricity was 

 fully demonstrated. His conjectures put to the test gave to 

 the service of humanity the lightning-rod, accounted the most 

 brilliant application of science that had been known up to 

 that time. 



In a hundred years, but little has been added to what 

 Franklin revealed concerning the electricity of friction. 

 Volta's electrophorus with his condenser and Holtz' induction 



