. Practical physics. Benjamin Franklin (1706-1790) Celebrated American statesman, philosopher, and scientist; bornat Boston, the sixteenth child of poor parents; printer and pub-lisher by occupation; pursued scientific studies in electricity asa diversion rather than as a profession; first proved that the twocoats of a Leyden jar are oppositely charged; introduced theterms positive and negative electricity; proved the identity oflightning and frictional electricity by flying a kite in a thunder-storm and drawing sparks from the insulated lower end of thekite string; invented the lightning rod;
. Practical physics. Benjamin Franklin (1706-1790) Celebrated American statesman, philosopher, and scientist; bornat Boston, the sixteenth child of poor parents; printer and pub-lisher by occupation; pursued scientific studies in electricity asa diversion rather than as a profession; first proved that the twocoats of a Leyden jar are oppositely charged; introduced theterms positive and negative electricity; proved the identity oflightning and frictional electricity by flying a kite in a thunder-storm and drawing sparks from the insulated lower end of thekite string; invented the lightning rod; originated the one-fluidtheory of electricity which regarded a positive charge as indi-cating an excess, a negative charge a deficiency, in a certainnormal amount of an all-pervading electrical fluid. Kite Exi-ekimknt In Jvine, 1752, Franklin demonstrated the identity of the electrie spark and light-ning. To prevent his kite from heing torn in the rain he made it of a silk handker-chief. The lower end of the kite string and a silk rihhon were tied to the ring of akey, and, to prevent any charge that might appear upon the string and the key fromescaping through his hody to the earth, he held the kite hy grasping the insulatingsilk rihhon. Standing under a shed to keep the rihhon dry, Franklin, hy presentinghis knuckle to the key, ohtained sparks similar to those produced hy his electricmachine. With these sparks he charged his Leyden jar and used it to give a , he performed with lightning all the experiments which lie hatl previouslyperformed with sparks from his frictional machine. The experiment is dangeroiisand should not he attempted hy inexperienced persons
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Keywords: ., benjaminfranklin, bookcent, bookdecade1920, electricity, lightning
