who invented slide rule and in what year
Slide rule The slide rule was invented around 1620â€“1630, shortly after John Napier's publication of the concept of the logarithm. In 1620 Edmund Gunter of Oxford developed a calculating device with a single logarithmic scale; with additional measuring tools it could be used to multiply and divide.[17] In c. 1622, William Oughtred of Cambridge combined two handheld Gunter rules to make a device that is recognizably the modern slide rule.[18] Like his contemporary at Cambridge, Isaac Newton, Oughtred taught his ideas privately to his students. Also like Newton, he became involved in a vitriolic controversy over priority, with his one-time student Richard Delamain and the prior claims of Wingate. Oughtred's ideas were only made public in publications of his student William Forster in 1632 and 1653.
Sound film The idea of combining motion pictures with recorded sound is nearly as old as the concept of cinema itself. On February 27, 1888, a couple of days after photographic pioneer Eadweard Muybridge gave a lecture not far from the laboratory of Thomas Edison, the two inventors privately met. Muybridge later claimed that on this occasion, six years before the first commercial motion picture exhibition, he proposed a scheme for sound cinema that would combine his image-casting zoopraxiscope with Edison's recorded-sound technology.[2] No agreement was reached, but within a year Edison commissioned the development of the Kinetoscope, essentially a "peep-show" system, as a visual complement to his cylinder phonograph. The two devices were brought together as the Kinetophone in 1895, but individual, cabinet viewing of motion pictures was soon to be outmoded by successes in film projection.[3] In 1899, a projected sound-film system known as Cinemacrophonograph or Phonorama, based primarily on the work of Swiss-born inventor François Dussaud, was exhibited in Paris; similar to the Kinetophone, the system required individual use of earphones.[4] An improved cylinder-based system, Phono-Cinéma-Théâtre, was developed by Clément-Maurice Gratioulet and Henri Lioret of France, allowing short films of theater, opera, and ballet excerpts to be presented at the Paris Exposition in 1900. These appear to be the first publicly exhibited films with projection of both image and recorded sound. Phonorama and yet another sound-film system—Théâtroscope—were also presented at the Exposition.[5]