Fruit: So that the watermelon will sit steadily, cut a very thin slice off its
least attractive side. Lay the watermelon on this cut side, then slice about 1/4
to 1/3 of the melon off the top. Set the piece aside.
With a melon baller, scoop out as much of the watermelon meat as possible. Discard
as many seeds as is practical. Spoon the balls into a large bowl. Scrape out the
remaining watermelon meat, and reserve it for another use.
Pour all the accumulated
juice into the bowl with the watermelon balls.
Cut the other melons in half, scrape
out their seeds, and scoop out balls of their meat as well. Add these to the watermelon
in the bowl, and lightly toss everything together.
Sauce: Stir together the ginger ale, jam or preserves and lime juice. If the
melons are not especially sweet, add the greater amount of jam to the sauce.
Pour the sauce over the melon balls, mixing gently.
Trim the top cut edge of the watermelon
shell to a smooth finish. Or you might zigzag it or shape it decoratively.
Refrigerate the melon balls and shell as long as several hours, until you are ready to serve
Shortly before serving, spoon the melon balls into the watermelon shell, piling
them attractively above the melon's rim. Garnish with mint.