HAMILTON — ON TIDES OF THE BAY OF FUNDY. 43 



of Shubenacadie river, near the bead of Cobequid bay. An 



impression has gone abroad and is popularly taken for granted, 



that here the tide attains the extraordinary maximum rise of 



seventj^-five feet, a greater vertical rise of tide than is known 



anywhere else in the world. All the old shipmasters and pilots 



about the Bay — many of them men of great experience and keen 



and acute observation — used formerly to declare that this was 



the case. 1 do not know what those of their class say now. 



1 find that, taking as a basis of calculation the vertical rise of 



spring tides at various other points about the bay and basin, as 



recorded on the latest Admiralty chart, and applying the rule 



which seems to apply to the tides of Cobequid bay, we are led 



to the conclusion that the rise of ordinary springs must, at the 



mouth of Shubenacadie river, considerably exceed sixty feet. 



I see no reason to doubt that during those exceptionally high 



spring tides, which take place occasionally under the combined 



influence of more than one of the heavenly bodies, the maximum 



rise, at the junction of the Shubenacadie and Truro channels, 



justifies the popular belief, and does attain to seventy-five feet. 



I furthermore think it not improbable that the vertical distance 



between high water and low Avater mark was formerly much 



greater than it is now ; and that formerly, at ordinary springs, 



there was cdivays a rise and fall of seventy-five feet at the mouth 



of the Shubenacadie. The low water level is being gradually 



raised owing to the fact that the channel is filling up. This 



applies to all the channels of the head waters of the Bay of Fundy. 



For instance, not more than twenty-five years since, vessels of 



from fifty to one hundred and fifty tons used, almost daily, to 



sail up this Cobequid bay to receive and discharge cargo at 



the place where it is now bridged, a short distance below the 



village of Truro. Now nobody ever attempts to take any sort 



of a craft above the class of an open boat, further up the 



bay than Yuill's island, which is about six miles below the 



bridge. The channel is obviously narrowing and becoming 



more shallow every year. The rapidity with which this is 



possible, may be imagined from the fact that during sj)rings, 



one tide flowing over a level space, Avill deposit a layer of 



mud a quarter of an inch thick. On the other hand, the 



