How Thomas Edison changed the world with his inventions
Have you heard of the American inventor and businessman Thomas Alva Edison? He is the father of many landmark inventions, including the phonograph, the modern light bulb, the electrical grid and motion pictures. Born in Ohio on 11th February, 1847, Edison learned and took up a job as a telegrapher, transmitting signals between the USA and Canada as he grew up. In an effort to improve the speed of the telegraph, he ended up inventing his first set of machines, the automatic telegraph, duplex telegraph, and the message printer. Here's a look at a few of his greatest inventions.
The phonograph
The tin foil phonograph was Edison's first significant innovation. The purpose of a phonograph was to record sounds and then replay them. It was developed while working with automatic repeaters of telegraph messages to increase their efficiency. During this process, Edison realised that the sound waves of speech could be indented onto an impressionable foil surface. He found that when played at a high speed, the machine's tape made a noise that sounded like spoken words. This intrigued him to try recording a phone message. He began experimenting with a telephone receiver's diaphragm by attaching a needle to it, assuming that the needle could puncture paper tape to record a message. His trials led him to use a stylus (pen-shaped instrument) on a tinfoil cylinder. Much to his amazement, this played back the short message he recorded, "Mary had a little lamb."
Edison's instrument, which played cylinders rather than discs, was known as a phonograph. The model for the first phonograph was completed on August 12, 1877. Since the patent was filed only in December, 1877 the model development was not finished until December. There were two needles on the machine: one each for recording and one for playback. When you spoke into the mouthpiece, the recording needle imprinted the sound vibrations of your voice onto the cylinder, appearing much like a graph. Thus, was born the cylindrical phonograph, the first machine capable of recording and reproducing sound!
Light bulb
Edison did not invent the light bulbs, rather he helped improvise upon the existing ones. When Edison started working on light bulbs, British inventors had already demonstrated that electric light was possible using an arc lamp.
The earliest bulbs had disadvantages such as having limited life and requiring high volumes of electric current to work. This made them difficult to commercialise on a big scale. So, Edison focussed on improving the filament, testing carbon followed by platinum, and finally settled for the carbon filament. By October 1879, Edison’s team had produced a light bulb with a carbonized filament of uncoated cotton thread that could last for 14.5 hours!
Later, Edison created a light bulb that lasted for several hours. He accomplished this by establishing a vacuum inside the bulb, replacing carbon with a bamboo filament and feeding the bulb a lower voltage. Voila! The bulbs started lasting for hours!
Following this success in 1878, Edison established the Edison Electric Light Company in New York City to produce bulbs for the masses. To quote this great inventor, “We will make electric light so cheap that only the rich will be able to burn candles”. The next year in December, 1879, Edison gave the first public demonstration of his incandescent light bulb.
Motion pictures
In 1888, English photographer Eadweard Muybridge visited Edison's laboratory in West Orange. It was Muybridge's idea that they combine Edison's phonograph with the former's zoopraxiscope, a device invented by the eminent photographer in 1879. It used to function by displaying a sequence of still photographs in rapid succession. Thus, Kinetoscope was born. The Kinetoscope was derived from the Greek words "kineto" (movement) and "scopos" (to watch). For the purpose of watching a film through a Kinetoscope, the film was cut into continuous strips and perforated along the edges. Then, it was pushed behind a shutter using sprockets (toothed wheel) in a stop-and-go manner. In 1891, Edison's team completed development of the Kinetoscope. Edison and his team filmed short films in his movie studio, known as Kinetographic Theatre. These short films were later viewed using the peep hole of the Kinetoscope. However, only one person at a time could view the movies! This was the the humble beginning of what we know as cinema today!