1. In large bowl of electric mixer, beat egg whites with cream of tartar and salt until whites hold soft peaks.

2. Gradually add ½ cup of the sugar, beating until whites are stiff but not dry. Transfer to another large bowl.

3. Put yolks in unwashed mixer bowl.

4. Beat until thick.

5. Add remaining sugar, 1 tbls at a time, beating yolks very thick and ivory colored.

6. Add lime rind, lime juice and water, beating until just blended.

7. Beat in flour at a very low speed or by hand.

8. Add mixture to egg whites mix, gently but thoroughly folding in with a rubber spatula.

9. Turn into ungreased 10" tube pan. Spread evenly.

10. Cut through batter several times with spatula to break up any air bubbles in batter.

11. Bake at 325°F for 1 hour or until tested done.

12. Invert on wire rack to cool.

13. Loosen cake from sides of pan with spatula.

14. Set on serving plate.

15. Sift powdered sugar over top, if desired.

16. Garnish with lime slices and leaves before serving.