In a saucepan, bring the apricots and the water to the boil over moderate heat.
Reduce the heat to low, cover the pan and simmer the apricots for 10 to 15 minutes or until they are tender.
With a slotted spoon, lift out the apricots and put them in a blender.
Blend at high speed until they are pureed.
Put the puree into a medium sized mixing bowl.
Stir in the lemon juice, sugar, brandy, macaroons and almonds.
Preheat the oven to moderate 350°F (Gas Mark 4, 180°C).
With the butter grease a 2 pint [1 1/2 quart] baking dish.
In a large bowl, beat the egg whites with a wire whisk or rotary beater until they form stiff peaks.
Using a metal spoon, fold the egg whites into the apricot mixture.
Pour the mixture into the baking dish.
Put the dish in a deep baking tin.
Pour in enough boiling water to come half way up the side of the dish.
Put the baking tin in the oven and bake for 25 to 30 minutes or until the top is lightly browned.
Remove the dish from the oven and set it aside to cool.
When it is cool put the whip in the refrigerator to chill for 1 to 1 1/2 hours before serving.