In 1973 the first mobile phone rang Motorola's rival

3 April 1973, Sixth Avenue, New York. Martin Cooper, head of communications at Motorola, pulls out a brick with an antenna, dials a number and holds it to his ear right outside the door of the Hilton.

On the other end Joel Engel answers, head of the rival project at Bell Labs, the AT&T division that had spent a decade promising the future of mobile telephony.

1. Cooper said, verbatim: «Joel, I'm calling you from a real mobile phone, held in my hand, walking down the street.» 2. Engel went quiet. Cooper counted nine seconds before hearing his answer. 3. He hung up and crossed the street without tripping: the gadget weighed a kilo and the batteries lasted twenty minutes.

Bell Labs did not put its mobile on sale until 1983. Motorola did not either: it took another ten years to slip that brick into a customer's hand. Cooper himself later admitted that the call had been, above all, to rub it in.