DIFFERENT FORMATION OF SEA-COASTS. Bi) 
roams along the coasts of ocean from zone to zone! what 
changes, as it wanders from the palm-girt coral island of the 
Beecny Head. 
tropical seas to the melancholy strands where, verging towards 
the poles, all vegetable life expires! and how magnificently grand 
does the idea of ocean swell out in our imagination, when we 
consider that its various shores witness at one and the same 
time the rising and the setting of the sun, the darkness of night 
and the full blaze of day, the rigour of winter and the smiling 
cheerfulness of spring ! 
The different formation of sea-coasts has necessarily a great 
influence on commercial intercourse. Bold mural coasts, rising 
precipitously from the deep sea, generally possess the best 
harbours. Rocky shores also afford many good ports, but 
most frequently only for smaller vessels, and of difficult access, 
on account of the many isolated cliffs and reefs which charac- 
terise this species of coast formation. 
In places where high lands reach down to the coast, the im- 
mediate depth of the sea is proportionably great; but wherever 
the surface rises gently landwards, the sea-bed continues with a 
corresponding slope downwards. On these flat coasts the tides 
roll over a sandy or shingly beach; and here the aid of human 
industry is frequently required to create artificial ports, or to 
prevent those already existing from being choked with sand. 
On many flat coasts the drift-sand has raised dunes, wearying 
