Wash the cucumbers, cut up and put into a preserving pan with the water. Simmer until a soft pulp. Put into a jelly bag and leave to strain overnight. Measure the juice and allow 1 lb. sugar, the juice of 1 lemon and a pinch of ginger to each pint of juice. Put over a low heat until the sugar has dissolved, then boil rapidly until setting point is reached. Pour into hot sterilized jars and cover tightly.