Note: This is an encore post from 2005 and originally appeared on the 1947project.

First-prize winner at the inventors exposition was Stanley Hiller Jr., who developed a helicopter in which two blades on a single shaft rotated in opposite directions, eliminating the need for a tail rotor.

Second-prize winner was Horace Pentecost, another helicopter developer who invented an engine and propeller that could be worn as a backpack.
Fourth prize went to John Pruner and Henry Krohn for a “color symphony machine.”

Third prize? It was awarded to a man named Joe Milan, who dreamed up an automotive accessory. Something he calls disk brakes.

The long-neglected Pan-Pacific burned to the ground in 1989.