Guitar Foundation of America is an American classical guitar organization, founded in 1973 at the National Guitar Convention sponsored by the American String Teachers Association. The company offer various services ranging from guitar lessons, to a guitar shop and events; the company is a nonprofit organization that relies on donation and advertising on its web site. In 1973, Thomas Heck wrote the foundations articles of incorporation, he has been the editor of the foundation's magazine. The foundation publishes Soundboard Scholar, a peer-reviewed journal, Prodigies, a magazine for children. In 1968, Heck was living in Vienna and collecting rare sheet music for guitar, including first editions by Mauro Giuliani. In 1973, he wrote the Articles of Incorporation in Santa Barbara, California, to create a non-profit foundation to which he could give his archive of sheet music, he created the archive in 1977 in Milwaukee while teaching at the Wisconsin Conservatory of Music. A catalog of the inventory was assembled and mailed to interested buyers, who could receive photocopies of sheet music on request.

A second edition of catalog was published four years later. During the 1980s, while Heck taught at Ohio State University in Columbus, the archive grew to include more sheet music and other materials related to classical guitar. In the 1990s, Heck was too busy to oversee the archive, so he sought someone to catalog it which turned out to be the University of Akron; some of the GFA Archive was entered online at Akron. The foundation holds Competition; the International Concert Artist Competition gives the following prizes to the winner: a recording contract, publishing contract, an international tour. The first competition took was held in 1982. Twenty-three guitarists entered the contest, these were reduced to four finalists. To become finalists, guitarists were required to play three pieces selected by the jurors. Michael Chapdelaine won the first contest, while Adam Holzman won in 1983. Holzman's repertoire included the Fourth Lute Suite by Sevilla by Albeniz. Official website The Guitar Foundation of America Archive at the University of Akron

A Leyden jar is an antique electrical component which stores a high-voltage electric charge between electrical conductors on the inside and outside of a glass jar. It consists of a glass jar with metal foil cemented to the inside and the outside surfaces, a metal terminal projecting vertically through the jar lid to make contact with the inner foil, it was the original form of the capacitor. Its invention was a discovery made independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden in 1745–1746; the invention was named after the city. The Leyden jar was used to conduct many early experiments in electricity, its discovery was of fundamental importance in the study of electrostatics, it was the first means of accumulating and preserving electric charge in large quantities that could be discharged at the experimenter's will, thus overcoming a significant limit to early research into electrical conduction. Leyden jars are still used in education to demonstrate the principles of electrostatics.

The Ancient Greeks knew that pieces of amber could attract lightweight particles after being rubbed. The amber becomes electrified by triboelectric effect, mechanical separation of charge in a dielectric; the Greek word for amber is ἤλεκτρον and is the origin of the word "electricity". Around 1650, Otto von Guericke built a crude electrostatic generator: a sulphur ball that rotated on a shaft; when Guericke held his hand against the ball and turned the shaft a static electric charge built up. This experiment inspired the development of several forms of "friction machines", that helped in the study of electricity; the Leyden jar was discovered independently by two parties: German deacon Ewald Georg von Kleist, who made the first discovery, Dutch scientists Pieter van Musschenbroek and Andreas Cunaeus, who figured out how it worked only when held in the hand. The Leyden jar is a high voltage device; the center rod electrode has a metal ball on the end to prevent leakage of the charge into the air by corona discharge.

It was first used in electrostatics experiments, in high voltage equipment such as spark gap radio transmitters and electrotherapy machines. Ewald Georg von Kleist discovered the immense storage capability of the Leyden jar while working under a theory that saw electricity as a fluid, hoped a glass jar filled with alcohol would "capture" this fluid, he was the deacon at the cathedral of Camin in Pomerania. In October 1745 von Kleist tried to accumulate electricity in a small medicine bottle filled with alcohol with a nail inserted in the cork, he was following up on an experiment developed by Georg Matthias Bose where electricity had been sent through water to set alcoholic spirits alight. He attempted to charge the bottle from a large prime conductor suspended above his friction machine. Kleist was convinced that a substantial electric charge could be collected and held within the glass which he knew would provide an obstacle to the escape of the'fluid', he received a significant shock from the device when he accidentally touched the nail through the cork while still cradling the bottle in his other hand.

He communicated his results to at least five different electrical experimenters, in several letters from November 1745 to March 1746, but did not receive any confirmation that they had repeated his results, until April 1746. Daniel Gralath learned about Kleist's experiment from seeing the letter to Paul Swietlicki, written in November 1745. After Gralath's failed first attempt to reproduce the experiment in December 1745, he wrote to Kleist for more information. Gralath succeeded in getting the intended effect on 5 March 1746, holding a small glass medicine bottle with a nail inside in one hand, moving it close to an electrostatic generator, moving the other hand close to the nail. Kleist didn't understand the significance of his conducting hand holding the bottle—and both he and his correspondents were loath to hold the device when told that the shock could throw them across the room, it took some time before Kleist's student associates at Leyden worked out that the hand provided an essential element.

The Leyden jar's invention was long credited to Pieter van Musschenbroek, the physics professor at University of Leiden, who ran a family foundry which cast brass cannonettes, a small business which made scientific and medical instruments for the new university courses in physics and for scientific gentlemen keen to establish their own'cabinets' of curiosities and instruments. Like Kleist, Musschenbroek was interested in and attempting to repeat Bose's experiment. During this time, Andreas Cunaeus, a lawyer, came to learn about this experiment from visiting Musschenbroek's laboratory and Cunaeus attempted to duplicate the experiment at home with household items. Using a glass of beer, Cunaeus was unable to make it work. Cunaeus was the first to discover that the experimental setup could deliver a severe shock when he held his jar in his hand while charging it rather than placing it on an insulated stand, not realising, the standard practice, thus making himself part of the circuit, he reported his experience to Allamand, Musschenbroek's colleague.

Allamand and Musschenbroek received severe shocks. Musschenbroek communicated the experiment in a letter from 20 January 1746 to René Antoine Ferchault de Réaumur, w