runching of a boat's keel upon its beach,
as some visitant from a neighboring isle comes to shear wool, gather
coco-nuts, catch birds or collect their eggs. All the 500 inhabitants of
the Westman Isles off the southern coast of Iceland live in one village
on Heimey, and support themselves almost entirely by fishing and fowling
birds on the wild crags of the archipelago.[945] An oceanic climate,
free contact with the Gulf Stream, and remoteness from the widespread
ice fields of Iceland give them an advantage over the vast island to the
north. Only twenty-seven of the ninety islands composing the Orkney
group are inhabited, and about forty smaller ones afford natural meadows
for sheep on their old red sandstone soil;[946] but Pomona, the largest
Orkney has 17,000 inhabitants on its 207 square miles of territory or 85
to the square mile. The Shetlands tell the same story--29 out of 100
islands inhabited, some of the _holms_ or smaller islets serving as
pastures for the sturdy ponies and diminutive cattle, and Mainland, the
largest of the group, showing 58 inhabitants to the square mile. This is
a density far greater than is reached in the nearby regions of Scotland,
where the county of Sutherland can boast only 13 to the square mile, and
Invernesshire 20. Here again insularity and contracted area do their
work of compressing population.

The causes of this insular density of population are not far to seek.
Islands can always rely on the double larder of land and sea. They are
moreover prone to focus in themselves the fishing industry of a large
continental area, owing to their ample contact with the sea. Shetland is
now the chief seat of the Scotch herring fishery, a fact which
contributes to its comparatively dense population. The concentration of
the French export trade of Newfoundland fish in little St. Pierre and
Miquelon accounts for the relatively teeming population (70 to the
square mile) and the wealth of those scraps of islands. So the Lofoden
Islands of Norway, like Iceland, Newfoundland and Sakhalin, balance a
generous sea against an ungenerous soil, and thus support a population
otherwise impossible.

[Sidenote: Oceanic climate as factor.]

For these far northern islands, the moderating effect of an oceanic
climate has been a factor in making them relatively populous, just as it
is on tropical isles by mitigating heat and drought. The prosperity and
populousness of the Bermuda Islands are to be explained larg