Archives September 2014

"Tape recording in your basement or bedroom used to be a freak thing. Now anybody can do it." Les Paul, musician At the end of the nineteenth century, Valdemar Poulsen developed the telegraphone as a means of recording sound on a magnetized wire. However, the sound quality of these machines was poor, and the wire itself was usually built into the machine, making it of little use for long-term audio storage. A breakthrough came in 1928 when German engineer Dr. Fritz Pfleumer (1881-1945) successfully fixed magnetic powder to a thin strip of paper. This was then able to record magnetic signals more effectively than magnetic wire. In 1930, the AEG company of Berlin began work on the magnetophone, an audio recorder that would make use of the Pfleumer principle. To develop the tape itself, it collaborated with another illustrious name in German electronics, BASF, which used its expertise in plastics more...

In 1902 American president Theodore Roosevelt went on a bear hunting expedition in Mississippi that led to the invention of perhaps the most iconic children's toy in history. Holt Collier, a former slave and prodigious huntsman, was charged with organizing the chase. In order to provide Roosevelt with a clear shot, Collier and his hounds tracked down a bear and drove it to the stand where the president was waiting. However, when Collier arrived with the bear, Roosevelt had left for lunch. In the ensuing confusion the bear attacked one of the hunting dogs. But unwilling to kill the beast he'd promised to the president, Collier simply knocked it out with his rifle and tied it to a tree. When Roosevelt returned a short while later he was impressed by Collier's feat, but refused to kill the defenseless bear. The episode gained widespread media attention, and in November 1902 the more...

"Engineering is the... art of applying science to the optimum conversion of natural resources." Professor Ralph J. Smith, Stanford University Die-casting is the name given to a process of producing identical and often complicated metal parts by forcing molten metal under high pressure into a reusable type of mold, which is known as a die. It is a four-step process. First the inside of the die is coated with a lubricant—used partly to help control the temperature of the mold, and partly to aid the removal of the cast when complete. Molten metal is then injected into the die under high pressure. Generally non ferrous metals are used in die-casting. Zinc is popular as it is easy to cast and has a low melting point, which increases the working lifespan of the die. Aluminum is also used as it is very lightweight. The metal is kept under pressure until the more...

The phonograph (gramophone) record was invented in 1887 by German-born, American inventor Emile Berliner (1851-1929). His flat, rotating disc involved the stylus moving horizontally across the record rather than vertically, as with the cylinders used previously. Berliner's recording stylus cut down on sound distortion and was easier to manufacture than the cumbersome wax cylinders. Early phonograph records were made from a mixture of hard rubber, cotton, and powdered slate, although shellac (a form of commercial resin) was later used after its introduction in 1896. Phonograph records were initially single sided but the double-sided disc became common after about 1923. They usually came in three standard sizes, 7-inch, 10-inch, and 12-inch, and originally they revolved at between seventy-five and eighty revolutions per minute (rpm). Most producers eventually settled on 78 rpm. A 10-inch disc would record about three minutes of music on each side. The discs used a spiral groove to more...