"Especially since the outside silver corners are plain." "Perhaps there is a secret spring hidden by the engraving," suggested Tom.

"Hunt around.

It may fly apart and let out a hundred thousand in diamonds." "Don't be foolish, Tom," said Dick.

"It isn't likely there is a spring." "But there just is a spring!" exclaimed Sam, who was handling the box.
"Hark!" He ran his finger nail over a spot on one side of the box, and there followed a tiny click.

Then he ran his finger nail back, and there was another click.
"Hurrah! Sam has solved the mystery of the sphinx!" cried Tom.