Indeed, these clouds resembled a billowy ocean of white foam in themselves, or a landscape covered with hills and valleys of snow.  The rounded cloud contours could easily be likened to the domes of snow-covered mountains.  It was really difficult to conceive that that amorphous expanse was not actually solid.  Here and there flocculent towers and summits heaved up, piled like mighty snow dumps, toppling and crushing into one another, as the breezes stirred them.