Ice

Water solidifies by cold at 32 deg. F. Salt-water ice in salt water floats with only one-ninth of its mass above water, and fresh-water ice in salt water floats with one-eighth of its mass above water. A wide expanse of ice is called a field, and one of smaller dimensions a floe; when a field is dissevered and broken into numerous pieces it is termed a pack; this, again, when of a broad shape is called a patch, and when much elongated a stream. When it is possible for a ship to sail freely through floating ice, the same is termed drift ice, and the ice itself is said to be loose or open. When the ice is crushed into fragments it is known by the name of brash ice. A portion of ice rising above the common level is called a hummock. The term sludge applies to the soft crystals which the frost forms when it first attacks the ruffled surface of the ocean, and when this sludge separates into small patches by the agitation of the water these patches are called pan cakes.