i9io] 
FORMATION OF THE PACK 
27 
encountering worse conditions than any ship has had 
before — worse, in fact, than I imagined would have been 
possible on any other meridian of those from which we 
could have chosen. 
'To understand the difficulty of the position you must 
appreciate what the pack is and how little is known of 
its movements. 
4 The pack in this part of the world consists (1) of the 
ice which has formed over the sea on the fringe of the 
Antarctic continent during the last winter ; (2) of very 
heavy old ice floes which have broken out of bays and 
inlets during the previous summer, but have not had 
time to get north before the winter set in ; (3) of com- 
paratively heavy ice formed over the Ross Sea early in 
the last winter ; and (4) of comparatively thin ice which 
has formed over parts of the Ross Sea in middle or 
towards the end of the last winter. 
'Undoubtedly throughout the winter all ice-sheets 
move and twist, tear apart and press up into ridges, 
and thousands of bergs charge through these sheets, raising 
hummocks and lines of pressure and mixing things up ; 
then of course where such rents arc made in the winter 
the sea freezes again, forming a newer and thinner 
sheet. 
'With the coming of summer the northern edge of 
the sheet decays and the heavy ocean swell penetrates 
it, gradually breaking it into smaller and smaller frag- 
ments. Then the whole body moves to the north and 
the swell of the Ross Sea attacks the southern edge of 
the pack. 
