62 THE TIDES OF THE BAY OF FUNDY—MURPHY. 
forces exerted do not give anything like the results equivalent 
to the initial degree of exertion at work at the entrance to 
the Bay. Itis generally observed that when any unusually high 
tides occur, such as from prevalent southerly winds, or from 
causes such as produced the Saxby tide, those extremely high 
tides will maintain themselves for several recurring oscillations. 
They seem to swing like a pendulum after receiving a sudden 
impulsive motion, until after some time they settle again into 
their normal condition. 
The tidal waves of the Bay of Fundy, as well as the waves 
of the atmosphere, teach us how great mechanical effects can be 
produced by the concentration of energy or power from small 
sources. The study of them may not only be interesting but 
instructive. 
