1706
Newton's Opticks
English physicist Sir Isaac Newton publishes Opticks, his collection of papers relating to light, color and optics. In it he outlines his corpuscular theory of light that holds that light is made up of particles, not waves, as other scientists had suggested.
1706
Friction = electricity
Francis Hauksbee of London invents an electrostatic generator composed of a glass sphere turned by a crank that produces an electric charge through friction. This is a significant improvement over the more primitive version produced by Otto von Guericke several decades earlier.1708
Insights into lightning
English scientist William Wall notes a similarity between thunder and lightning and the cracking sounds and sparks produced by electrified objects. His observations are published in Philosophical Transactions.
1709
Studies in electroluminescence
Physico-Mechanical Experiments on Various Subjects. Containing an Account of Several Surprizing Phenomena Touching Light and Electricity is published by Francis Hauksbee and becomes an important early work in the areas of electricity and electroluminescence.
1716
The Northern lights
English mathematician and astronomer Edmond Halley correctly speculates that the atmospheric phenomenon of aurorae is related to the effects of the magnetic field of the Earth.
1722
True and magnetic north
Through close observation of the needle of a compass, London instrument maker George Graham discovers the diurnal variation of magnetic declination.
1729
Surface charge
Chemist Stephen Gray of London demonstrates the conductivity of electricity and determines that it is the surface of an object that holds its charge.
1733
Two types of electricity
French chemist Charles-François de Cisternay du Fay speculates that there are two different types of electricity, which he refers to as resinous (-) and vitreous (+), notes the repulsion of like charges and the attraction of unlike charges, and determines that string is more conductive when wet.
1742
Principia edition
Thomas Le Sueur and Francis Jacquier publish an edition of Isaac Newton’s Principia and include a note to the text that demonstrates an inverse-cube law of the force between two magnets.
1745
Leyden jar
The Leyden jar, the first practical device for storing electric charge, is invented independently by German cleric E. Georg von Kleist and Dutch physicist Pieter van Musschenbroek.1745
Continuous electricity
Jean-Antoine Nollet, a French clergyman and physicist, theorizes that electrical matter continuously flows between two charged objects.
1745
Longer life for magnets
English physicist Gowin Knight develops a method of producing artificial magnets that retain their magnetization for extended periods of time. The new magnets are used in the Knight compass, which becomes very popular among mariners and scientists.
1746
Human conductors
In a demonstration of electricity for King Louis XV, Jean-Antoine Nollet discharges a Leyden jar so that the current passes through a line of 180 Royal Guards. He would later carry out a similar feat involving a chain of Carthusian monks that extended more than a kilometer.
1746
Theory of conservation
British scientist William Watson develops the concept of the conservation of electrical charge, in which there exists a single electrical fluid that is not created or destroyed, but only transferred from one object to another. Soon after, Benjamin Franklin more fully develops the theory of conservation.
1746
Trying to telegraph
Johann Heinrich Winckler, a professor at the University of Leipzig, tries to use electricity to communicate telegraphically across long distances.
1747
Measuring conductivity
English physicist and chemist Henry Cavendish begins measuring the conductivity of various substances by comparing the shocks he receives when he discharges Leyden jars through them.
1748
Electric velocity
William Watson, Henry Cavendish and other colleagues attempt to measure the velocity of electricity as it traveled through a circuit more than 12,000 feet long and mistakenly conclude that it is instantaneous.
1748
Early electroscope
Jean-Antoine Nollet builds an early electroscope, an electrometer comprised of a suspended pith ball that moves in response to the electrostatic attraction and repulsion of a charged body.