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sheep not

ships.

London-Watling Street. Some may doubt that Limen was the ancient name of the Rother. Or that the Saxon Limenemouth meant either the mouth of the port or the mouth of the River Limen. They now bear But no one can doubt that Hythe and Romney, which are both inland now were once Cinque Ports; and impossible as it may appear to some, it is equally certain that within historical times all the harbours of the alluvial Rother have been 'swarved up,' and now bear sheep instead of ships.

Now 62,000 acres, worth perhaps £200,000 a year rent, are not formed by an igneous crack certainly. What did form them? Rain and rivers, and rain and rivers in forming them sent a million times 62,000 acres into the sea, which is quite enough to account for alluvial valleys and a delta, where once stood the highest part of the anticlinal ridge of the Weald Hill.

The alluvial plains of the Medway, and of the Great and Little Stour, have grown as rapidly as the delta of the Rother. And Portus Rutupiensis, like the harbours of the delta, bears sheep not ships, in the form of 25,000 acres of rich pasture. These dry acres are formed by deposit from water. If they had been raised by subterranean fire, the beach on which the Romans built at Dover would also have been raised.

Suppose that we modestly estimate that the

entire earth is covered each year with a yard of rain, and that, speaking loosely, this enormous body of water returns to the sea through the rivers. Every one must perceive that the nearer the mouth the more water the river has to discharge. The fall of water and consequent denudation on the hill-top is, as they would say, arithmetical, there is no accumulation there. But the accumulation and aggregation of water, and denudation is in a geometrical ratio as we proceed from the hill to the sea. The consequence is the cutting of the river channel below low water, a broad horizontal alluvial valley, with a lazy-flowing, mud-collecting (and mud-depositing) river.'

CHAPTER IV.

THE ST. LAWRENCE WILL RUN THROUGH RIDGES BY

PONDING.

RIVERS MAY RUN THROUGH RIDGES OF HILLS BY PONDING, AS IN THE VALLEY OF ST. LAWRENCE. LYELL CONTRADICTS HIMSELF ON THIS SUBJECT. THE AMERICAN LAKES ARE

BEING LAID DRY BY RAIN. THIS WILL HAPPEN WITHOUT ANY APPARENT CHANGE. TWO MINIATURE WEALD VALLEYS ORIGIN OF THE CHINES. ORIGIN WEALD.' ANSWER TO LYELL'S

IN THE ISLE OF WIGHT.

OF THE NAME OF THE

QUESTION, AT WHAT PERIOD WAS THE WEALD VALLEY DENUDED ?'

THE hill of the Weald and the valley of the St. Lawrence seem to have as little to do with each other theoretically, as practically they are far apart. Yet as each illustrates one of two modes in which nature drives her rivers across and through ridges of hills, I shall consider the two as one subject in two chapters.

Lyell writes of the valleys of the Weald hill: 'If these transverse hollows could be filled up, all the rivers,' observes Mr. Conybeare, would be forced to take an easterly course, and to empty themselves into the sea by Romney Marsh and Pevensea Levels.' To this we may add that then,

and in that case, the Weald would be a valley with one lower outlet; and if we prolong our ifs, we may also prolong our valley.

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For if the English Channel were filled up, and if the North and South Downs ran across it, and joined the chalk borders of the Seine, the waters of the Weald would help the Seine to drown Paris. And if Hampshire and the banks were high enough, and all the transverse hollows in France could be filled up,' the rain which falls on Nore Hill would run through the railroad tunnel above Dijon, and so by the Saone and Rhone to the Mediterranean. But τι ει ουρανος εμπεσοι ; this if appears to me inexpressibly childish, as also does one of Lyell's own ifs ('Principles').

If the high ground between the heads of Lake Superior and of the valley of the Mississippi were to sink by a series of successive subsidences,' the lake would be emptied into the Gulf of Mexico instead of the North Atlantic. 'If the event happened in a dry season, when the ordinary channels of the Mississippi and its tributaries are in a great degree empty, the inundation might not be considerable; but if in the flood season, a region capable of supporting a population of many millions might be suddenly submerged.' But Lyell forgets that the lake is filled by the rain and rivers of the high land, and that as the high land

sank by a series of successive subsidencies,' the lake would gradually become a dry valley. But now, after having abused the ifs of others, I will have an if of my own, or rather in conjunction with Lyell. He himself shows us that this lake, and all the American lakes are at this instant quietly in process of becoming dry valleys, without any violence, or any catastrophe, or any cataclysm; that's the word, because people would understand you if you used the word flood. In direct contradiction to his own theory that all valleys are formed by submarine denudation, he says (Principles'), The falls of Niagara afford a magnificent example of the progressive excavation of deep valley in a solid rock.' The cataract is now 165 feet in height. 'When it began to recede, it must have had nearly twice its present height.' Say 300 feet.

a

Lyell thinks that the river forms this gorge at the rate of one foot in a year, and would therefore have taken 35,000 years to form the present seven miles. Mr. Bakewell allows a yard a year, reducing the period to below 12,000 years. There are yet fifteen miles of gorge to make before the river begins to let off Lake Erie.

Now here is a grand if. If, 50,000 years after this (don't laugh, there have been 50,000 50,000 years before this), Lyell, Martin, Hopkins, and

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