When the two met, the Sawai Man Singh Hospital was turning out only five or six artificial limbs a year, mostly for people injured in road and train accidents, and a few of the wealthier patients wore American-model limbs. Both were too expensive for the common man, and neither permitted very much mobility. Besides, as Sethi explains, the old artificial limb was a cultural misfit not just for Indians but for people in most developing countries. "We sit, eat, sleep and worship on the floor--all without shoes," he says. Also, the "shoe" attached to the old limb was made of heavy sponge, making it worthless for any farmer working in the rain or in irrigated paddies.

Watching Sethi's patients, Chandra became convinced that he could fashion a more lifelike--and useful--artificial limb. He took his proposals to Sethi, who explained to the barely literate craftsman about pressure points and the intricate movements of bones within the foot. For two years, the two men fashioned limbs out of willow, sponges and aluminum molds, but their experiments failed. Their choices proved to be either too fragile or too unwieldy. "We made all kinds of silly mistakes," says Sethi.

Then one day, while riding his bicycle to the hospital, Chandra ran over a nail, and his tire went flat. He wheeled his bicycle to a roadside stall, where the repairman was busy retreading a truck tire with vulcanized rubber. Once his bicycle was fixed, Chandra raced to the hospital and consulted with Sethi. Soon Chandra returned to the tire shop with an amputee patient and a foot cast. He asked the repairman if he could cast a rubber foot. "He agreed,'' Sethi says, "and refused to accept any money once he found out why we were doing it."

Rubber alone was not good enough; it shredded within a few days. It was only after Chandra and Sethi began to construct the rubber foot around a hinged wooden ankle--wrapping it in a lighter rubber (similar to a bicycle inner tube but flesh colored) and then vulcanizing this composite--that their invention succeeded. The resulting limb takes only 45 minutes to build and fit onto the patient and is sturdy enough to last for more than five years. Sethi says of his partner, "We had a lot of opposition from formally trained doctors. In a way, someone who's not so educated is much more free."