42 
from one ocean to the other, entering the Arctic circle from the Pacific and 
returning home by the Atlantic, not however accomplishing the passage in 
his ship but partly over the solid ice. 
Beset in September 1846 by ice in about latitude 70 p the Erebus and 
Terror were abandoned in April 1848 after drifting 19 miles south, Sir 
John Franklin having died on the 11th June 1847. The crews under 
Captain Crozier appear to have attempted to reach the American Continent 
over the ice and to have perished on the way, most probably from hunger. 
The prolonged absence of this expedition gave rise to many others to 
ascertain its fate and to these belong the honour of most of the subsequent 
geographical discoveries in these regions. 
The author next proceeded to describe the natural phenomena of the 
polar regions beginning with Ice. 
The polar year consists only of summer and winter, their limits being 
determined by the breaking up and re-formation of the sea-ice. The 
breaking up of the winter ice is sometimes accelerated a month or two, or 
delayed an equal length of time by circumstances the causes of which are 
unknown. In August 1838 Dease and Simpson found the sea about 
Coronation Gulf a mass of fixed ice and could only progress on foot along 
the shore, whilst the following year a month earlier they ran past the same 
coast with a fresh breeze, a flowing sail, and an open sea. The great mass 
of the sea-ice does not remain stationary through the winter and melt 
away in summer but is in constant though slow motion, mostly in the direction 
of the lower latitudes where it is finally broken up and dispersed. Captain 
Back in the Terror was helplessly borne along amidst the most frightful 
commotion of the surrounding ice, from Eepulse Bay through Hudson 
Strait, until liberated after many months in Davis Strait. The wonderful 
drift of the Fox down Baffin's Bay from August 1857 to April 1858, by 
which McClintock was delayed a whole year in his search for the Franklin 
expedition, was another illustration of the above fact. 
The immense floating masses called icebergs consist of fresh water ice 
formed on the coasts and broken off by the action of the waves. The rocks 
of ice from which they have been severed are huge glaciers advancing far 
into the sea. When the buoyant power of the ice overcomes the attraction 
of cohesion masses break off at the bottom of the sea and rise to the surface 
in the form of bergs. As they float with only a tenth of their bulk above 
the water, the rate of movement of the glacier, the distance of its front 
from the sea, and the depth of the water near the shore have been made the 
