38 PHYSICAL GEOGRAPHY OF THE SHA. 
so as fully to explain all the particulars of the sublime phe- 
nomenon. 
The reproach has often been made to science, that she 
banishes poetry from nature, and disenchants the forest and 
the field; but this surely is not the case in the present instance, 
for what poetical fiction can fill the soul with a grander image 
than that of the eternal restlessly-progressing tide-wave, which, 
following the triumphant march of the sun and moon, began as 
soon as the primeval ocean was formed, and shall last uninter- 
ruptedly as long as our solar system exists ! 
Were the whole earth covered with one sea of equal depth, 
the tides would regularly move onwards from east to west, and 
everywhere attain the same height under the same latitude. 
But the direction and the force of the tide-wave are modified by 
many obstacles on its way, such as coast-lines and groups of 
islands, and it has to traverse seas of very unequal depth and 
form. Flat coasts impede its current by friction, while it rolls 
faster along deep mural coasts. From all these causes the 
streneth of the tides is very unequal in different places. 
They are generally low on the wide and open ocean. Thus 
the highest tides at Otaheiti do not exceed eleven inches, three 
feet at St. Helena, one foot and a half at Porto Rico. 
But when considerable obstructions oppose the progress of the 
tide-waves, such as vast promontories, long and narrow channels, 
or bays of diminishing width, and mouths of rivers directly facing 
its swell, it rises to a very great height. Thus, at the bottom of 
Fundy Bay, which stretches its long arm between Nova Scotia 
and New Brunswick, the spring-tides rise to sixty, seventy, or 
even one hundred feet, while at its entrance they do not exceed 
nine feet, and their swell is so rapid as frequently to sweep 
away cattle feeding on the shore. 
The Bristol Channel and the bay of St. Malo in Brittany, are 
also renowned for their high tides. Near Chepstow, the flux 
is said sometimes to reach the surprising height of seventy feet, 
and at St. Malo the floods frequently rise to forty and fifty feet. 
When the water is low, this small seaport town appears sur- 
rounded on all sides by fantastically shaped cliffs covered with sea- 
weeds and barnacles. Pools of salt water interspersed here and 
there among the hollowed stones, or on the even ground between 
them, and harbouring many curious varieties of marine animals, 
