Another time, an engineer was developing a prototype for a six-cylinder engine.

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The women played around with different designs and consulted with Ms. Teich's father, an aerospace engineer, about creating a prototype and writing a patent.

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Before leaving the Bell Rocket Belt, it's worth noting that Mr. Li's essential innovation powering a jetpack by way of a pressurized umbilicus is exactly how Bell engineer Wendell Moore tested his first prototype in the late 1950s, except Mr. Moore used nitrogen gas instead of water.

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For example: An Internet-jacked kettle that alerts us when the national power grid is overloaded (a prototype has been developed by U.K. engineer Chris Adams) doesn't prevent us from boiling yet another cup of tea, but it does add an extra ethical dimension to that choice.

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Also still employed, at least according to his LinkedIn page, is Gray Powell, the Apple engineer who lost possession of an iPhone 4 prototype, yielding Gizmodo and Gawker Media their biggest traffic bonanza ever.

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The phone in question was a prototype of the iPhone 4G, which had not yet been released, and the guy was a software engineer at Apple who was out celebrating his twenty-seventh birthday.

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