Put a three-quart mould in a wooden pail, first lining the bottom with
    fine ice and a thin layer of coarse salt. Pack the space between the
    mould and the pail solidly with fine ice and coarse salt, using two
    quarts of salt and ice enough to fill the space. Whip one quart of
    cream, and drain it in a sieve. Whip again all the cream that drains
    through. Put in a small pan one ounce of 
 Chocolate, three tablespoonfuls of sugar and one of boiling water,
    and stir over a hot fire until smooth and glossy. Add three
    tablespoonfuls of cream. Sprinkle a cupful of powdered sugar over the
    whipped cream. Pour the chocolate in a thin stream into the cream, and
    stir gently until well mixed. Wipe out the chilled mould, and turn the
    cream into it. Cover, and then place a little ice lightly on top. Wet a
    piece of carpet in water, and cover the top of the pail. Set away for
    three or four hours; then take the mould from the ice, dip it in cold
    water, wipe, and then turn the mousse out on a flat dish.