Before video games and robotics competitions, toys were much simpler: girls got dolls; boys got model trains and bicycles. Toys that promoted learning and experimentation were rare until one inventor, Alfred Carlton (“A. C.”) Gilbert, started making toys that taught children about science and engineering. His most famous, the Erector set, became one of the best -selling toys of its day and inspired children across the country to build everything from bridges to robots.

Gilbert was a man of many talents. He financed his medical degree from Yale University by working as a magician, invented the pole-vaulting box and won a gold medal in the sport in 1908, and broke the world record for consecutive chin-ups—39 in a row. In 1918 he became "the man who saved Christmas" by convincing Congress not to ban toy production during the war.

But he is most famous for his toys. Gilbert founded the A. C. Gilbert Company and went on to invent and sell all kinds of classic science toys from chemistry sets to robots to microscopes. Gilbert's real innovation was to provide kids with a way to experiment with real-life tools and parts, says William Brown, director of the Eli Whitney Museum in Hamden, Conn., where a large collection of Gilbert toys is on display. "They had that feel of being not symbolic but part of the real world," he says. "You were working with a motor for your Erector set that could actually move heavy things."

And that real-life appeal did not just apply to kids. In 1949 doctors at the Yale School of Medicine used an Erector set to build a precursor to the modern artificial heart.

At the time of Gilbert's death in 1961, he had patented more than 150 toys. But his company was faltering and, by 1967, it went out of business. There was a new generation of entertainment, Brown says: television. Gilbert's toys were a product of the radio generation. "You could listen to the radio and spend all 19 hours that it takes to build the Ferris wheel" from the Erector set, Brown says. Once television sets made it into people's homes, that time went away.

Today those toys remind us of the power of creativity and of how important it is to let kids play and learn. "The way to teach kids about tools is not to tell them what to be afraid of," Brown says, "but how to use them, and that's what Gilbert did."

Here, Scientific American takes a look at some of the classic A. C. Gilbert toys.

» View a slide show of classic Gilbert toys.

(Thanks to the Eli Whitney Museum for providing the classic toy ads.)