16 
ing it, I have followed the account given 
by the accurate Pennant in his Arctic 
To the north of Mainland is an Island 
called Yell, which is twenty miles long 
and nearly twelve broad. It has several 
good harbours, or voes, as they are cal¬ 
led by the inhabitants. 
There is another Island to the west of 
Mainland, called Foula. It is about 
three miles long, and one and a half 
broad, and has only one harbour. This 
is called Ham, and is much resorted to 
by fishermen. Foula is thought by some 
to be that Island which the ancients 
reckoned the ultimate limit of the habi¬ 
table globe, and to which, therefore, they 
gave the appellation of Ultima Thule. 
This supposition is not formed only from 
the mere analogy of the name, but also 
from the authority of Tacitus, who, 
speaking of the victories obtained by 
Agricola, and how far he penetrated 
4 
