field ice is more formidable than the fields and floes of new ice that are formed during a single winter, and which during the following summer are known by polar voyagers as "one-year ice." At the beginning of winter they may show a thickness of possibly five or perhaps ten feet, and in places there will be even thicker pieces. Then comes a whole winter's intense frost, snow falls and adds to the weight and thickness, and when this ice breaks up the following spring we have a really formidable pack to encounter. When such pack ice is not very open, but still open enough for a protected ship to work its way through, the ship has to be handled with the greatest care even when navigating through it in fine weather. This ice cannot be charged indiscriminately like one-year ice, and one must be able to distinguish between one piece of ice and another. This can only be done by one who has had many years of experience of polar ice-navigation.
One piece, a heavy-looking mass, may be charged and will be shattered; another, a wise ice-master will avoid charging because he knows it is of steely hardness and that his ship will make no impression upon it. A careful ice-master never touches a piece of ice if he can avoid doing so at any time, in spite of his stout ship, the full strength and
