into the warmer waters. But the bergs remain when all traces of the pack
have disappeared, and, drifting northwards still, form the menace to
shipping so well known to sailors rounding the Horn. It is not hard to
imagine that one monster ice island of twenty miles in length, such as do
haunt these seas, drifting into navigated waters and calving into
hundreds of great bergs as it goes, will in itself produce what seamen
call a bad year for ice. And the last stages of these, when the bergs
have degenerated into 'growlers,' are even worse, for then the sharpest
eye can hardly distinguish them as they float nearly submerged though
they have lost but little of their powers of evil.

There are two main types of Antarctic berg. The first and most common is
the tabular form. Bergs of this shape cruise about in thousands and
thousands. A less common form is known as the pinnacled berg, and in
almost every case this is a tabular berg which has been weathered or has
capsized. The number of bergs which calve direct from a mountain glacier
into the sea is probably not very great. Whence then do they come?

The origin of the tabular bergs was debated until a few years ago. They
have been recorded up to forty and even fifty miles in length, and they
have been called floe bergs, because it was supposed that they froze
first as ordinary sea-ice and increased by subsequent additions from
below. But now we know that these bergs calve off from the Antarctic
Barriers, the largest of which is known as the Great Ice Barrier, which
forms the southern boundary of the Ross Sea. We were to become very
familiar with this vast field of ice. We know that its northern face is
afloat, we guess that it may all be afloat. At any rate the open sea now
washes against its face at least forty miles south of where it ran in
the days of Ross. Though this Barrier may be the largest in the world, it
is one of many. The most modern review of this mystery, Scott's article