12 lemons, thinly sliced
3 cups white sugar
4 trays ice cubes
8 cups cold water
Thinly slice lemons crosswise. Try to remove as many seeds as possible. Put lemon slices into a large punch bowl. Pour sugar over the top of the lemons. Using a potato masher or wooden spoon, pound lemons and sugar mixture until sugar is dissolved and lemon slices are broken.
Add ice cubes and stir in cold water. Serve in tall glasses.