Scott puzzled over the framework again. He experimented. This time there were no shocks, even slight. The abacus had showed him the correct method. Now it was up to him to do it on his own. The bizarre angles of the wires seemed a little less confusing now, somehow.
It was a most instructive toy —
It worked, Scott thought, rather like the crystal cube.

Mimsy Were The Borogoves (1943)