An everyday invention that I use a lot is telephone .It was invented in 1973 by Martin Cooper .Before that time people used letter to communicated.It mand of glass, plastic and metal.
A senior engineer at Motorola, called a rival telecommunications company and informed them he was speaking via a mobile phone. The phone Cooper used, if you could call it that, weighed a staggering 1.1kg and measured in at 228.6x127x44.4mm. With this prototype device, you got 30 minutes of talk-time and it took around 10 hours to charge.
The first mobile phones went on sale in the U.S. at almost $4,000 each.Over 250 million Nokia 1100 devices were sold, making it the bestselling electrical gadget in history.It's usedful because everyone to used communication.