Phonograph cylinderPhonograph cylinders are the earliest commercial medium for recording and reproducing sound. Commonly known simply as "records" in their heyday (c. 1896–1916), these hollow cylindrical objects have an audio recording engraved on the outside surface, which can be reproduced when they are played on a mechanical cylinder phonograph. In the 1910s, the competing disc record system triumphed in the marketplace to become the dominant commercial audio medium.
Frame rateFrame rate (expressed in or FPS) is typically the frequency (rate) at which consecutive s (frames) are captured or displayed. This definition applies to film and video cameras, computer animation, and motion capture systems. In these contexts, frame rate may be used interchangeably with and refresh rate, which are expressed in hertz. Additionally, in the context of computer graphics performance, FPS is the rate at which a system, particularly a GPU, is able to generate frames, and refresh rate is the frequency at which a display shows completed frames.
ShellacShellac (ʃəˈlæk) is a resin secreted by the female lac bug on trees in the forests of India and Thailand. Chemically, it is mainly composed of aleuritic acid, jalaric acid, shellolic acid, and other natural waxes. It is processed and sold as dry flakes and dissolved in alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and wood finish. Shellac functions as a tough natural primer, sanding sealant, tannin-blocker, odour-blocker, stain, and high-gloss varnish.
Picric acidPicric acid is an organic compound with the formula (O2N)3C6H2OH. Its IUPAC name is 2,4,6-trinitrophenol (TNP). The name "picric" comes from πικρός (pikros), meaning "bitter", due to its bitter taste. It is one of the most acidic phenols. Like other strongly nitrated organic compounds, picric acid is an explosive, which is its primary use. It has also been used as medicine (antiseptic, burn treatments) and as a dye. Picric acid was probably first mentioned in the alchemical writings of Johann Rudolf Glauber.
Exposition Universelle (1889)The Exposition Universelle of 1889 (ɛkspozisjɔ̃ ynivɛʁsɛl) was a world's fair held in Paris, France, from 5 May to 31 October 1889. It was the fourth of eight expositions held in the city between 1855 and 1937. It attracted more than thirty-two million visitors. The most famous structure created for the Exposition, and still remaining, is the Eiffel Tower. The Exposition was held to celebrate the 100th anniversary of the Storming of the Bastille, which marked the beginning of French Revolution, and was also seen as a way to stimulate the economy and pull France out of an economic recession.
