80 



A HISTORY OF 



fend the land, and only are interrupted here 

 and there to give an egress to rivers, and to 

 grant the conveniences of bays and harbours 

 to our shipping. It may be in general re- 

 marked, that wherever the sea is most vio- 

 lent and furious, there the boldest shores, 

 and of the most compact materials, are found 

 to oppose it. There are many shores several 

 hundred feet perpendicular, against which 

 the sea, when swollen with tides, or storms, 

 rises and beats with inconceivable fury. In 

 "the Orkneys, where the shores are thus form- 

 ed, it sometimes, when agitated by a storm, 

 rises two hundred feet perpendicular, and 

 dashes up its spray, together with sand, and 

 other substances that compose its bottom, 

 upon land, like showers of rain. 



Hence, therefore, we may conceive how 

 the violence of the sea, and the boldness of 

 the shore, may be said to have made each 

 other. Where the sea meets no obstacles, 

 it spreads its waters with a gentle intume- 

 scence, till all its power is destroyed, by 

 wanting depth to aid the motion. But when 

 its progress is checked in the midst, by the 

 prominence of rocks, or the abrupt elevation 

 of the land, it dashes with all the force of its 

 depth against the obstacle, and forms, by its 

 repeated violence, that abruptness of the 

 shore which confines its impetuosity. Where 

 the sea is extremely deep, or very much vex- 

 ed by tempests, it is no small obstacle that 

 can confine its rage ; and for this reason we 

 see the boldest shores projected against the 

 deepest waters; all less impediments having 

 long before been surmounted and washed 

 away. Perhaps of all the shores in the world, 

 there is not one so high as that on the west 

 of St. Kilda, which, upon a late admeasure- 

 ment, 1 ' was found to be six hundred fathom 

 perpendicular above the surface of the sea. 

 Here, also, the sea is deep, turbulent, and 

 stormy ; so that it requires great force in the 

 shore to oppose its violence. In many parts 

 of the world, and particularly upon the coasts 

 of the East Indies, the shores, though not 

 high above water, are generally very deep, 

 and consequently the waves roll against the 

 land with great weight and irregularity. 

 This rising of the waves against the shore, is 



* BufTon, vol. ii. p. 191. b Description of St. Kilda. 



called by mariners the surf of the sea; 

 and in shipwrecks is generally fatal to such 

 as attempt to swim on shore. In this case, 

 no dexterity in the swimmer, no float he can 

 use, neither swimming girdle nor cork jacket 

 will save him; the weight of the superincum- 

 bent waves breaks upon him at once, and 

 crushes him with certain ruin. Some few of 

 the natives, however, have the art of swim- 

 ming and of navigating their little boats near 

 those shores, where an European is sure of 

 instant destruction. 



In places where the force of the sea is less 

 violent, or its tides less rapid, the shores are 

 generally seen to descend with a more gra- 

 dual declivity. Over these, the waters of the 

 tide steal by almost imperceptible degrees, 

 covering them for a large extent, and leav- 

 ing them bare on its recess. Upon these 

 shores, as was said, the sea seldom beats 

 with any great violence, as a large wave has 

 not depth sufficient to float it onwards; so 

 that here only are to be seen gentle surges 

 making calmly towards land, and lessening 

 as they approach. As the sea, in the former 

 description, is generally seen to present pros- 

 pects of tumult and uproar, here it more usu- 

 ally exhibits a scene of repose and tranquil 

 beauty. Its waters, which when surveyed 

 from the precipice, afforded a muddy greenish 

 hue, arising from their depth and position to 

 the eye, when regarded from a shelving 

 shore, wear the colour of the sky, and seem 

 rising to meet it. The deafening noise of the 

 deep sea is here converted into gentle mur- 

 murs ; instead of the water's dashing against 

 the face of the rock, it advances and recedes, 

 still going forward, but with just force enough 



i to push its weeds and shells, by insensible 



| approaches, to the shore. 



There are other shores, beside those al- 

 ready described, which either have been 

 raised by art to oppose the sea's approaches, 

 or, from the sea's gaining ground, are threat- 

 ened with imminent destruction. The sea's 

 being thus seen to give and take away lands 

 at pleasure, is, without question, one of the 

 most extraordinary considerations in all na- 

 tural history. In some places it is seen to 

 obtain the superiority by slow and certain 



Newton's Optics, p. 163 167- 



