This 1939 design for a solar powered folding car is interesting and a bit silly, but was based on the predictions of a Professor about a future of stronger materials and metals.
What requires so much weight in automobile engines or bodies, in giant bridges, in the steel frames of buildings and a thousand other things is that so much metal must he used to make the beams or castings strong. Weight Itself is useless. The need is only for strength.It is a great point, so much of the energy used in cars goes to moving the mass of metal of the car rather than the contents.
"Great strides have been made recently," Professor Harrison writes, "in the physics of metals—the study of how atoms cling together to form crystals and these crystals hang together in metal rods and wires. All metals are permeated by microscopic cracks and flaws which greatly reduce their strength.
"If only the crystals of which they are composed would hang to one another with the forces with which the individual atoms cling together! Then a cable of steel an inch thick would safely support four million pounds, instead of the mere 300,000 pounds which it now will held."
Such metals 13 times stronger than now can mean not only lighter engines and folding, fly-weight auto bodies, but also taller buildings, longer bridges, faster airplanes, larger ships--or deadlier machine guns and farther-ranging submarines.
the appropriately named San Antonio Light interpreted this to envision the lightweight, folding car.
Even the young man of the scientific future may find trouble, one day on the road, with his sunpower automobile. He gets out, tips up the car with one hand and looks underneath. Finding what seems to be the trouble, he unscrews a few clamps, takes out the engine, and starts off jauntily to the repair shop, as though he were only carrying an alarm clock.
Strong muscles? Not at all, merely a lightweight engine.
Next day he comes back for the engineless car, folds it up like a collapsible baby carriage, loads it on the most convenient high speed bus or aero bus, takes it home and tucks it away in any handy closet until the engine has been repaired.