At first they had all floundered hopelessly about, and it had taken some practice even to slide a few steps; but long before they had reached the stage of skimming over the frozen surface at the rate of eight or ten miles an hour, which had been their fond ambition, the snow had melted into moist and dirty slush, which was particularly trying, as they had just decided to make a sledge out of an old packing-case, and drag Lilian round the pasture.