a8 THE TIDES OF THE BAY OF FUNDY—MURPHY. 
“Briar Island and Long Island. into the Bay of Fundy.” And 
in p.66: “At the south entrance of St Mary’s Bay the flood 
“sets N. E. by N. at the rate of 7 knots.” 
As in nature everything is repeated when similar conditions 
occur, we must, by not concealing even what is still imperfectly 
observed, call attention of future observers to special phenomena. 
According to my observations, it must not be forgotten that 
besides the crowding movements of the currents which we have 
followed so far, movements with very different forces, as for 
instance, the meeting of currents advancing from opposite direc- 
tions caused by the tide itself, may take place. Currents of water, 
like currents of air meeting from various directions, create gyra- 
tions and form whirlpools. The celebrated Maelstrom, on the coast 
of Norway, is caused by such a contlict of streams. The late 
Admiral Beechey, R. N., in an interesting paper on tidal streams 
of the North Sea and English Channel,* gave diagrams illustra- 
tive of many rotatory streams, a number of which occur 
between the outer extremities of the channel tide and the 
oceanic or parent wave, and says-——“ they are clearly to be 
accounted for by the streams acting obliquely on each other.” 
Here in the bell mouth of this funnel or trough-shaped 
bay, we may again follow with the very simple assumption— 
that it is by this conflict of currents the water is still more 
lifted by crowding and rotatory action and continues onward 
as the flood increases, thus imparting the progressive lifting 
movement as far as Cape Chiegnecto, a distance of 100 miles. 
The confluence of these currents setting along converging coasts, 
—first marked by the tide rips between Briar Island and 
Mount Desert—impinging obliquely and rolling up the Bay with 
enormous progressive motion, create a vast force of horizontal 
translation; and this action is nearly as powerful at a great 
depth as at the surface. Such a wave, reflected from a rigid 
body, would produce a hydraulic pressure equal to that due to 
a little more than double its own height; a roller of 20 feet 
high would produce a pressure of over a ton per foot. 
The tide floods the Bay of Fundy from Grand Manan to Cape 
*See Phil, Transactions, Part 11, 1851, on Tidal Streams of the North Sea and English Channel. 
