400 years ago on the River Thames a mad genius showed off the world's first submarine. A crowd of thousands including King James watched as Cornelis Drebbel disappeared beneath the murky water, only reemerging after three whole hours had passed.

The same genius also came up with perpetual motion machines, self-regulating ovens, chemical air conditioning for Westminster Cathedral, and a project to provide central heating for all of London by building a perpetual fire on a hill outside the city, transporting the flames in pipes to people's houses.

Elon Musk eat your heart out.

Dallas's guest today is the amazing Vera Keller, historian of technology and author of a new book "The Interlopers: Early Stuart Projects and the Undisciplining of Knowledge"

Edited by Tom Delargy, Produced by Freddy Chick, Senior Producer is Charlotte Long

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