When was the electrostatic machine invented?
Franklin's electrostatic machine
Franklin invented the lightning rod based on what he learned from experiments with his electrostatic machine. [11][41] Franklin and his associates observed that pointed objects were more effective than blunt objects at "drawing off" and "throwing off" sparks from static electricity.[12][42] This discovery was first reported by Hopkinson.[19] Franklin wondered if this discovery could be used in a practical invention. [43] He thought something could be made to attract the electricity out of storm clouds, but first he had to verify that lightning bolts really are giant electric sparks.[43] He wrote Collinson and Cadwallader Colden letters about this theory.[44] The 1752, Franklin letter to Collinson of October 19 of the kite experiment is noted by historian LeMay as a basis how it proved that lightning was electricity.[45] Tom Tucker of the Isothermal Community College doubts the account, however, because of ambiguities in the account and points that out in his book Bolt of Fate: Benjamin Franklin and his Electric Kite Hoax.[46][47] Others disagree with this view, arguing that Franklin would not make up such a fake story because he valued the integrity of the scientific community.[48][49]