Today, human and machine endurance. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

A friend passed along a 1991 issue of a Human-Powered Vehicle Journal. It was about radical bicycles, about the elusive challenge of making a human-powered helicopter, and high-speed pedal-driven boats. It dealt with the challenge of driving every kind of powered vehicle without the help of an engine. And I realized this was about reclaiming a place for human stamina in our age-old dream of faster, higher, further. I suspect my interest was jogged by the morning paper; tennis champion Roger Federer had just endured the longest winning Grand Slam game ever played. 

While the very purpose of machines throughout history has been to relieve the need for human endurance, our delight in our capacities remains alive and well. It keeps drawing inventors to the interface of technology and human stamina. The organization that published this journal has wrestled with other organizations over who should wear the mantle of this cause. But that only reflects the passion driving the pursuit of machine-aided endurance. 

One important thread in this endeavor is the Kremer Prize. Just as Lindbergh was driven to win the Orteig Prize for the man/machine endurance of a solo flight, New York to Paris, others now compete for Kremer's many human-powered flight prizes.

Henry Kremer, born in Latvia in 1907, emigrated to England after WW-I and was educated in Switzerland. He became an inventor of wood products. The deHavilland Mosquito was an amazing WW-II low-altitude light bomber made of wood in the era of aluminum. It was built from Kremer's special laminated plywoods. 

Kremer kept inventing, forming companies, and working with the Royal Air Establishment. But he also took a strong interest in human fitness; and that led to his prizes. Three have been won so far; two more are pending. In 1977, Paul McCready won £75,000 when cyclist Bryan Allen flew a one-mile course in his pedal-powered Gossamer Condor. Two years later, he won £100,000 for flying the English Channel in his Gossamer Albatross. An MIT design group won a third £20,000 Kremer prize for speed -- flying one mile at 20 miles-an-hour. 

Two more prizes hang like high lush fruit upon a tree. One challenge is to fly a 26-mile marathon in less than an hour. The other is to fly a carefully specified aerial sporting event. Other prizes pend: The Sikorsky prize will go to the first person who can stay aloft for a minute in a human-powered helicopter and reach a height of ten feet. 

So the lure remains -- human endurance coupled with machines. And it's not frivolous. The effort constantly demands better efficiency and it creates ideas that carry over into our more familiar engine-powered world. And, most important, this odd pursuit continues to give our own bodies a role in our ongoing quest for excellence. It reminds us that, engines or no, our vehicles all remain wed to our fragile selves.

I'm John Lienhard at the University of Houston, where we're interested in the way inventive minds work.

I'm grateful to Roger Kaza for the journal behind this episode: HUMAN POWER: The Technical Journal of the IUHPVA, Vol. 9, No. 2, Summer 1991. Images: Kremer courtesy of the Royal Air Establishment, Daedalus photo by J. Lienhard. Other images courtesy of Wikipedia commons.

The Gossamer Albatross, first human-powered aerial crosser of the English Channel.

Daedalus: Human-powered airplane that made it from Crete to Santorini.