National Geographic : 1898 Sep
ATLANTIC ESTUARINE 1IDES St John River Tides 0 I II III IV V VI VII H. W. interval from Indiantown. 0 19 10 8 8 10 10 10 H. W. advance in last hour (miles). 26 15 11.5 10.3 9.7 8.6 7.7 6.2 Mean tide range (inches). h.mh.m.h.m . . m.h.m.h.m.h.m.h.m. 540516516516517517518448Durationofrise. 645797979787877737Durationoffall. At Fredericton, over 70 nautical miles from Indiantown, the mean levels are 14 feet 4 inches above mean sea-level. The rail road levelings are used in this determination and may be open to some doubt; but Young asserts that tide runs 100 feet above sea in the Amazon,* and Airy t says the same thing happens in the Firth of Clyde, and, moreover, should happen from theory. As the wave progresses upstream 10 miles an hour, it is not to be supposed that the water poured inward from the Bay of Fundy travels upstream to cause the rise of water. The water is merely set oscillating. The Indiantown tides are themselves two hours later than the tides at St John, and the five-inch wave that reaches Springhill, 78 nautical miles upstream, spends over nine hours in the transit. Salt water is said to be detected 48 miles up the river, which is surprising. PENOBSCOT TIDES Penobscot bay has its outer waters so full of islands that the tidal bay must be counted to have its mouth from Camden to Castine. Thence to Bangor the ranges mount up steadily-9.7, 9.8, 10.2, 10.6, 12.0, 13.1 feet in 26 miles. The times indicate a clear retardation, though the series is short. Tide passes from Matinicus, the outer island, to Bangor in two hours. Above Bangor the river part is cut off by falls, and no river part is present. Only depth of water and freedom from sediment can allow such tides in a narrow channel. KENNEBEC TIDES The tide progresses from the sea to Augusta (45 miles) in four hours, with somewhat irregular speed and diminishing range. * General Astronomy, p. 258. t Encycl. Metropolitana, vol. iii, p. 338.