28 
SCOTT'S LAST EXPEDITION 
[December 
* This makes it clear why at the northern and southern 
limits the pieces or ice-floes arc comparatively small, 
whilst in the middle the floes may be two or three miles 
across ; and why the pack may and does consist of various 
natures of ice-floes in extraordinary confusion. 
* Further it will be understood why the belt grows 
narrower and the floes thinner and smaller as the summer 
advances. 
' Wc know that where thick pack may be found early 
in January, open water and a clear sea may be found in 
February, and broadly that the later the date the easier 
the chance of getting through. 
*A ship going through the pack must cither break 
through the floes, push them aside, or go round them, 
observing that she cannot push floes which are more 
than 200 or 300 yards across. 
'Whether a ship can get through or not depends on the 
thickness and nature of the ice, the size of the floes and 
the closeness with which they arc packed together, as 
well as on her own power. 
4 The situation of the main bodies of pack and the 
closeness with which the floes arc packed depend almost 
entirely on the prevailing winds. One cannot tell what 
winds have prevailed before one's arrival ; therefore one 
cannot know much about the situation or density. 
'Within limits the density is changing from day to 
day and even from hour to hour ; such changes depend 
on the wind, but it may not ncessarily be a local wind, 
so that at times they seem almost mysterious. One 
sees the floes pressing closely against one another at a 
