Exploring Electrical Technology Reaction to Ben Franklin’s Electricity & Lightning Rod

Drama in the French Academy Abbe Nollet Abbe Nollet –Member –Respected lecturer –Authority on electricity with a 2-fluid theory Promoted it widely Promoted it widely Used it to explain the Leiden Jar Used it to explain the Leiden Jar

Drama in the French Academy Comte de Buffon Comte de Buffon –Rival and superior to Nollet –Previously snubbed by Nollet –Seeking revenge, he found Franklin’s book –Had Franklin’s book translated into French Translation done by Dalibard Translation done by Dalibard Put forth Franklin’s book to challenge Nollet Put forth Franklin’s book to challenge Nollet Nollet’s 2-fluid vs. Franklin’s 1-fluid theory

Drama in the French Academy Dalibard Dalibard –In 1752 he upstaged Nollet before the king Showed the king some of Franklin’s experiments Showed the king some of Franklin’s experiments Later that year followed an experiment suggested by Franklin to become the 1 st to draw electricity from a thunderstorm Later that year followed an experiment suggested by Franklin to become the 1 st to draw electricity from a thunderstorm –An account of his experience with lightning Shared at the academy Shared at the academy Began the pursuit of drawing “fire” from clouds (a.k.a. thunderbolt collecting) Began the pursuit of drawing “fire” from clouds (a.k.a. thunderbolt collecting)

Drama in the French Academy Franklin’s book & experiments Franklin’s book & experiments –Challenged Nollet –Fueled debate and discussion: served to further promote Franklin’s notoriety

Franklin’s Side Proposed drawing lightning from the sky Proposed drawing lightning from the sky –Before his book was published in 1751 –Such an exp’t not actually tried until 1752 Had not yet done it himself Had not yet done it himself Franklin’s kite experiment Franklin’s kite experiment –Devised and carried out before news of the experiment in France reached him –Importance of the pointed collecting rod being grounded: stated but not always observed

Lightning Collecting Popular: a “sport” in the interest of science Popular: a “sport” in the interest of science Casualites Casualites –occurred due to lack of safety precautions –George Wilhelm Richmann Most famous example Most famous example Conducted his lightning rod exp’t at the Academy in St. Petersburg Russia Conducted his lightning rod exp’t at the Academy in St. Petersburg Russia Inadequate grounding killed him in his attempt Inadequate grounding killed him in his attempt –Evident danger restrained others –Provided negative press for Nollet against Franklin That Franklin escaped such dangers: a miracle? That Franklin escaped such dangers: a miracle?

Impact: Franklin’s Lightning Rod Practical applications: by 1752, major buildings in Philly had lightning rods Practical applications: by 1752, major buildings in Philly had lightning rods Guarded acceptance: lightning rods were not without controversy Guarded acceptance: lightning rods were not without controversy Superstitions revealed: throughout Europe at the time, during thunderstorms, churches rang bells to ward off lightning bolts ! Superstitions revealed: throughout Europe at the time, during thunderstorms, churches rang bells to ward off lightning bolts !

To Use the Rod or Not? Superstitious view Superstitious view –Lightning as tool of evil forces: repelled by ringing the bells –Result: Bell ringers reported to have been killed by thunderbolts (as electricity passed from the bell down the cord) Effectiveness of the Rod Effectiveness of the Rod –Widely accepted: by academics and researchers from 1752 on –Resisted: by common people who viewed it as an attempt to alter or replace the ways of God with science

Franklin Fails to Convince Most Church Leaders Franklin: unsurprised by resistance commented that 1000 years of experience speaks otherwise to the effectiveness of bell-ringing to dissipate lightning and suggested that maybe a new “trick” was in order Franklin: unsurprised by resistance commented that 1000 years of experience speaks otherwise to the effectiveness of bell-ringing to dissipate lightning and suggested that maybe a new “trick” was in order Church leaders: also generally opposed to lightning rods, with a few rare exceptions Church leaders: also generally opposed to lightning rods, with a few rare exceptions Conclusion: ignorance & superstition played a large role in the slow acceptance of lightning rods, especially in Europe Conclusion: ignorance & superstition played a large role in the slow acceptance of lightning rods, especially in Europe

Nollet Opposes Rod Motivation: his still wounded pride at being upstaged by many of Franklin’s discoveries Motivation: his still wounded pride at being upstaged by many of Franklin’s discoveries Authority: continued to be well-known and respected Authority: continued to be well-known and respected Approach: highlighted tragedies like Richmann and other isolated cases where buildings had been destroyed due to inadequate grounding to blame and discredit Franklin’s Rod Approach: highlighted tragedies like Richmann and other isolated cases where buildings had been destroyed due to inadequate grounding to blame and discredit Franklin’s Rod

Should Rods be Pointed or Blunt? Wilson Wilson –Member of the RSL –Argued for blunt Franklin: argued for points Franklin: argued for points Issue became political Issue became political –Pointed rods blamed for minor damage to British powder magazines in late 1770s –Wilson, funded by George III, made blunt rods British practice vs. American colonies & Franklin’s points What do the Van De Graff and video demonstrations reveal on this issue?

Summary on Franklin’s Reputation 1 of most noted & respected scientists in his day, despite only 9 years of exp’ts 1 of most noted & respected scientists in his day, despite only 9 years of exp’ts Much more respected overseas since Much more respected overseas since –Greater spirit of science & invention existed in Europe than as yet in the colonies –Academics undeveloped in colonies during his lifetime (Franklin started 1 st learned society)

Summary on Franklin’s Theory Held a 1-fluid theory that challenged Nollet’s prevailing 2-fluid theory Held a 1-fluid theory that challenged Nollet’s prevailing 2-fluid theory Called an object with excess fluid “electrised positive” and one with a lack of such fluid “electrised negative” Called an object with excess fluid “electrised positive” and one with a lack of such fluid “electrised negative” Thought the fluid attracted ordinary matter but repelled itself, but failed to explain repulsive forces between two negatively charged objects Thought the fluid attracted ordinary matter but repelled itself, but failed to explain repulsive forces between two negatively charged objects

Franklin’s Contributions One-Fluid Theory of Electricity One-Fluid Theory of Electricity Terms Positive (+) & Negative (-) Terms Positive (+) & Negative (-) Demonstrated electricity in Nature (lightning electricity same as gen. in lab) Demonstrated electricity in Nature (lightning electricity same as gen. in lab) Principle of Conservation of Charge Principle of Conservation of Charge Electrostatic induction & conduction Electrostatic induction & conduction Recommended practice of grounding Recommended practice of grounding Invented the Lightning Rod Invented the Lightning Rod

Significance of Lightning Rod (Beyond its Practical Value) Electrical phenomena occur in nature Electrical phenomena occur in nature –On quite a large scale –An actual force of nature Confirmed Bacon’s prediction Confirmed Bacon’s prediction –1 st significant example –Scientific discoveries in natural world lead to major practical inventions Promoted value of lightning experiments in the war against superstition Promoted value of lightning experiments in the war against superstition

Contemporaries of Franklin Beccaria: an Italian chair of physics at the University of Turin (1748) Beccaria: an Italian chair of physics at the University of Turin (1748) –Expt’d with lightning rod & thoroughly examined the phenomenon –Published a treatise supporting Franklin’s discoveries entitled Del l’eletticismo Artificiale e naturale in 1753

Contemporaries of Franklin Aepinus: an applied mathematician, astronomer at Berlin Academy in Germany (1755) Aepinus: an applied mathematician, astronomer at Berlin Academy in Germany (1755) –Studied Franklin’s work & translated it into German –Extended Franklin’s 1-fluid theory to explain why 2 negative forces repel –Quantified Franklin’s observations with surprising accuracy –In 1759 published a reformulation of Franklin Overlooked by his contemporaries Overlooked by his contemporaries Inaccessible and unreadable due to its math & Latin Inaccessible and unreadable due to its math & Latin

Contemporaries of Franklin Priestly: an English clergyman, political theorist and physical scientist Priestly: an English clergyman, political theorist and physical scientist –Met Franklin in London –Elected member of RSL in 1766 based on his electrical experiments –Encouraged by Franklin to summarize work on knowledge of electricity to date on knowledge of electricity to date In 1767 pub. The History and Present State of Electricity In 1767 pub. The History and Present State of Electricity –Predicted inverse square law of electrical attraction based on his own observations –Interest turned toward chemistry as he saw chemical changes brought about by electricity

Contemporaries of Franklin Cavendish: a wealthy, unsociable, Cambridge educated physicist Cavendish: a wealthy, unsociable, Cambridge educated physicist –Deepened and extended Aepinus work in his classic paper of 1771 –Exemplified how far one could go in physics with concepts, mathematics and apparatus –Clever experiments led him also to deduce that the law governing electrical forces depended on the inverse square of distance btwn electrified objects –Saw no need to publish, so received no credit

Contemporaries of Franklin Coulomb: a French physicist, experienced military engineer Coulomb: a French physicist, experienced military engineer –Assisted in becoming a member of Paris Academy by winning a prize competition Involved the variation of Earth’s magnetism typically measured by a needle on a pivoted point Involved the variation of Earth’s magnetism typically measured by a needle on a pivoted point Based on his knowledge of ropes, he perceived performance would be improved by suspending the needle from a silk thread allowing it to oscillate freely in a horizontal plane Based on his knowledge of ropes, he perceived performance would be improved by suspending the needle from a silk thread allowing it to oscillate freely in a horizontal plane Concluded that restoring force torsion was proportional to the angle of twist Concluded that restoring force torsion was proportional to the angle of twist

Coulomb Discovers and Gets Credit for Inverse Square Law (ISL) After perfecting prize winning technique with small mechanical forces After perfecting prize winning technique with small mechanical forces –Went on to electricity –Precisely measured electrical force between objects as it depended on distance and amounts of charge to establish ISL –Published his findings in Not immediately accepted outside France Not immediately accepted outside France But by 1800, few questioned it anywhere But by 1800, few questioned it anywhere See also Coulomb’s ingenious torsion balance pictured in Electricita.

Instrumentation During the 4 th Period ( ) Devices invented and developed to both generate large amounts of charge as well as measure small amounts of it sensitively Devices invented and developed to both generate large amounts of charge as well as measure small amounts of it sensitively –Electrometer (1766 by de Soussure) Measured electric potential by means of attraction or repulsion of charged objects Measured electric potential by means of attraction or repulsion of charged objects A version was incorporated into Coulomb’s balance A version was incorporated into Coulomb’s balance –Electrostatic machine (1768 by Ramsden) Used glass plates to generate charge Used glass plates to generate charge –Electroscope (gold leaf version in 1786 by Bennet) Perhaps most sensitive way of meas. elect. charge of its time Perhaps most sensitive way of meas. elect. charge of its time

Era of Early Electrical Science Ends; Launches A New Age of Electricity Instrumentation sets the stage at the end of the 18 th century for the turn of the 19 th Instrumentation sets the stage at the end of the 18 th century for the turn of the 19 th Enter two Italians Enter two Italians –Luigi Galvani –Allessandro Volta Their contribution launched electricity into the age of truly life changing applications Their contribution launched electricity into the age of truly life changing applications