Along with Erector Sets®, Legos®, Lincoln Logs® and K’NEX®, Tinkertoys® are a type of building toy on the Toy Industry Association’s list called “Century of Toys” — the 100 tops toys of the twentieth century. Created in 1913, the same year as Erector Sets®, Tinkertoys® was invented by two Evanstonians: Charles H. Pajeau and Robert Pettit, the inspiration being children building with empty spools of thread and pencils.

Most Tinkertoy® pieces are made of wood and are very similar to the original design. The basic types of pieces include:

• Rods: color-coded by length, these sticks of identical diameter have a slot in each end to hold a flag, if desired.

• Elbows: plastic pieces, bent in the middle, connect rods at an angle.

• Couplings: plastic pieces that can connect two rods end to end and — in its middle hole — can rotate around another.

• End caps: plastic pieces that tidily cover rod ends.

• Spools: wooden hubs that accept rods around their circumference and through a hole in their center. Unlike the couplings, the center hole secures the rod, not allowing the spool to rotate.

• Flags: thin green plastic quadrilaterals that serve as flaps, wings, or arms.

• Pulleys: round pieces with a center hole like that in a spool and an indentation to hold a string.

More advanced sets include plastic tubes, pods, pod couplings, and pod hangers, and rail holders, as well as connector clips, a face plate, and robot arms. The tubes allow curves to be added to the designs.

All kits include a design guide with building ideas. Sample ideas include a race car, a robot, an airplane, a helicopter, and a castle. This brings up a point about how children can use Tinkertoys®. On the one hand, Tinkertoys® can be used to help children work from a model and follow directions. On the other hand, Tinkertoys® also give children scope for imaginative play, in which they simply explore the possibilities offered by the elements of the set to create an abstract or specific, planned or improvised structure.