The riddle
What Has Four Legs but Cannot Walk?
Legs without feet
A table has four legs and no way to use them. In furniture, a leg is a vertical support, not a limb for walking. Benches and stools use the same word for their supports. The riddle starts from an animal image, four legs, and ends at an object that cannot move. A table also has a top, and often an apron, the strip under the top that joins the legs together.
A chair works too
Many tellers answer a chair, and the answer is just as good, since a chair has four legs and stays put. A table is the one most often named first. Another four-legged riddle adds a head and a foot: what has one head, one foot and four legs.
Why four legs can wobble
Any three points that are not in a straight line lie in exactly one flat plane, so a three-legged stool always rests firmly on a floor, even an uneven one. That is also why cameras and surveying instruments stand on tripods. Four feet need not all touch the floor at once, which is why a table on uneven ground can rock until something is folded and slipped under one leg.
Where the word table comes from
Table traces back through Old English and French to the Latin tabula, a board or plank. The word was a flat surface before it was furniture with legs.