Hourglasses 1 Puzzle

The Puzzle:

Hourglasses 1

You need to boil eggs for exactly 9 minutes, or else the visiting Duchess will complain, and you will lose your job as head chef.

But you have only 2 Hourglasses, one measures 7 minutes, and the other measures 4 minutes. How can you correctly measure 9 minutes?

Do you have the answer? Check against our solution!