1 82 Arctic and Antarctic Exploration [part i 
reindeer-skin shirts, leather boots lined with fur, a fur 
cap, and reindeer-skin gloves. The party had a reindeer- 
skin conical tent, 12 feet across on the ground and 10 feet 
high, with a light framework of six poles. When they 
camped they lighted a fire in the centre of it, and were 
half smothered by the smoke. Each man slept on a bear- 
skin, and there was a reindeer-skin coverlet for every two. 
In his first journey Wrangell surveyed the coast from 
the mouth of the Kolyma eastward to Cape Chelagskoi, 
with the temperature sometimes as low as — 31 0 Fahr. 
His second journey, starting on March 27th, 182 1, was 
undertaken to see how far he could go over the ice to the 
northward, away from the Siberian coast. At a distance 
of two miles from the shore the party had to cross a chain 
of high and rugged hummocks five miles wide. Beyond, 
the ice was fairly level, but after advancing for 140 miles 
Wrangell found the ice to be weak and rotten owing to 
large patches of brine being lodged on the snow. It was 
therefore deemed prudent to commence their retreat on 
April 4th. They returned to Nijni Kolymsk on the 28th 
after an absence of 36 days, having travelled over 800 
miles, averaging 22 \ miles a day. 
Wrangell was much struck by the wonderful skill 
displayed by the sledge drivers in finding their way by 
the wave-like ridges of snow formed by the wind. These, 
formed on the level sea ice by any wind of long continu- 
ance, are called sastrugi in Siberia. The ridges always 
indicate the quarter from which the prevailing winds blow. 
The inhabitants of the tundras often travel over several 
hundred miles with no other guide than these sastrugi. 
They know by experience at what angle they must 
cross the greater and lesser waves of snow in order to 
arrive at their destination, and they never err. It often 
happens that the true permanent sastrugi have been 
obliterated by temporary winds, but the traveller is not 
deceived. His practised eye detects the change, he 
carefully removes the recently drifted snow, and corrects 
his course by the lower sastrugi, and by the angle formed 
by the two. 
On his third journey, Wrangell started northwards 
from the coast on March 16th, 1822, chiefly with the 
object of ascertaining the truth of a native rumour that 
