Aquapac
Aquapac is a registered trademark and brand name of a UK-based manufacturing company, Aquapac International Limited, specializing in waterproof cases and bags. The privately owned company was formed in 1983 and holds patents worldwide on systems for sealing bags and cases. The range commenced with a waterproof case for the original Sony Walkman known as the ‘Aquaman’, followed by cases for handheld VHF radios. Following Motorola’s invention of the first cellphone Aquapac launched the world’s first waterproof cellphone case. Nokia was an important customer for these cases during the 1990s, as were cellphone operators such as Deutsche Telekom and NTT DoCoMo. Aquapac went on to launch waterproof cases for other handheld electronics such as cameras and eReaders. The company operates out of factories in London, England.
Invention of the telephone
After Bell and Watson discovered on June 2, 1875, that movements of the reed alone in a magnetic field could reproduce the frequencies and timbre of spoken sound waves, Bell reasoned by analogy with the mechanical phonautograph that a skin diaphragm would reproduce sounds like the human ear when connected to a steel or iron reed or hinged armature. On July 1, 1875, he instructed Watson to build a receiver consisting of a stretched diaphragm or drum of goldbeater's skin with an armature of magnetized iron attached to its middle, and free to vibrate in front of the pole of an electromagnet in circuit with the line. A second membrane-device was built for use as a transmitter. This was the "gallows" phone. A few days later they were tried together, one at each end of the line, which ran from a room in the inventor's house, located at 5 Exeter Place in Boston, to the cellar underneath. Bell, in the work room, held one instrument in his hands, while Watson in the cellar listened at the other. Bell spoke into his instrument, "Do you understand what I say?" and Watson answered "Yes". However, the voice sounds were not distinct and the armature tended to stick to the electromagnet pole and tear the membrane.