52 THE TIDES OF THE BAY OF FUNDY—MURPHY. 
phenomenal trade winds. The fisherman also profits by the 
great height of the tide which, during the flood, comes with its 
large shoals of such fish as resort to the coast. These remain to 
feed until the return or ebb tide falls somewhat, and are trapped’ 
within wiers of wattles, that are made to run out past 
their line of retreat. Large quantities of herring, cod and shad 
thus left dry at low water, are carted tc the smoke-houses 
prepared and packed in small cases and forwarded to the different 
markets. Smoked cod and herring from Digby, (“ Digby 
Chickens ”) obtained in this way, form important items of export. 
If we look at the bending of the great waves, as shewn by 
Whewall’s chart of co-tidal lines around the continents of Africa 
and Europe, they seem to trend very like that sort of refraction 
which takes place on every shelving shore with respect to the 
common waves, which, whatever may have been their origin 
become always, as they spread, more and more, nearly parallel to 
that of the coast which they are approaching. 
The tides result from the disturbing influence of the bodies 
within the Solar System, which cause a constant changing of the 
position of the ocean in accordance with their changes of posi- 
tion in relation to the surface of the earth; but they are not 
currents, they are merely undulations or oscillations of the 
ocean, although where obstructed by coast lines they form cur- 
rents about the coast. 
The ocean currents result from the great cosmical force of 
gravitation, drawing in all directions from the centre of the 
earth opposing terrestrial gravitation drawing towa'ds earth’s 
centre; thus forming a system of circulation within the position 
in which the ocean is held by gravitation without tending to 
change that position in relation to the surface of the earth ; and 
these ocean currents would exist, even if the earth were not 
affected by the bodies of the Solar System, so that currents such 
as the Gulf Stream have no relation whatever to tidal movements. 
The height of the tide is less in mid ocean than along the 
coast, and is greatly augmented where two coast lines converge. 
At St. Helena the rise is two or three feet; at the Azores three 
feet; and on the Atlantie coast of the United States from five 
