of Refuge on the East Coast of Scotland. 309 



river has succeeded in forcing a passage, and in making for 

 itself a channel towards low water-mark, this new course be- 

 comes exposed to ripple action, and will be speedily obliterated 

 to a certain extent, whenever the quantity and velocity of the 

 water become reduced. This is strikingly illustrated in the 

 condition of many of the rivulets which empty themselves into 

 the bay of Aberdeen, to the north of the river Don, and may 

 be observed with but little modification in the Don itself. 



In general, therefore, it will bo found, that when a river, after 

 traversing a valley, falls into a bay of the sea having its shore 

 covered with moveable materials, it has to contend with this 

 character of the beach, to have its contents continuously dis- 

 tributed, and hence a bar must be formed of the materials 

 carried into deeper water, while its distance from the shore 

 will depend on the weakness or strength of the stream, and 

 its shape be modified by the currents of the passing tides. 



The banks of rivers invite the settlement of a population, 

 from the superior fertility of the soil in the neighbourhood, 

 the accompanying shelter, and the supply of water for personal 

 and domestic purposes. Hence the early peopling of the banks 

 of rivers. 



The mouths of rivers were first selected as harbours by the 

 neighbouring population, being in some measure ready-made^ 

 contiguous to the most fertile spots, and sufficiently convenient 

 for all the ordinary purposes of a local and limited trade. But, 

 in an expanded state of maritime enterprize, they exhibit de- 

 fects of no ordinary magnitude, such indeed as would justify 

 us in considering a river as a nuisance rather than a benefit 

 to a harbour.* 



The bars of sand or shingle, to which we have referred, pro- 

 duce shallow water at the entrance, and prevent the shipping 

 from passing and repassing, with equal facility, at all times of 

 the tide. The river, too, in the state of flood, passes out to 



* The opinion here expressed receives a practical illustration from the 

 harbour of Leith, originally selected, from being the mouth of the water of 

 Leitb, Its inconveniences for modem traffic led to the erection of the 

 Newhaven Pier; then the Chain-Pier; and, lastly, to the magnificent har- 

 bour of Granton, — excellent, because without a river, and destined at no 

 distant period to become the Port of Edinburgh. 



vol.. XXXIV. NO. LXVIII. APRIL 1843. X 



