Scientific Essays and Lectures

by Charles Kingsley

2. Or by a mighty current? If so, the flood must have run in at the upper end, before it ran out at the lower. But nothing has run in at the upper end. All round above are the undisturbed gravel-beds of the horizontal moor, without channel or depression.

3. Or by water draining off a vast flat as it was upheaved out of the sea? That is a likely guess. The valley at its upper end spreads out like the fingers of a hand, as the gullies in tide-muds do.

But that hypothesis will not stand. There is no vast unbroken flat behind the glen. Right and left of it are other similar glens, parted from it by long narrow ridges: these also must be explained on the same hypothesis; but they cannot. For there could not have been surface-drainage to make them all, or a tenth of them. There are no other possible hypotheses; and so he must fall back on the original theory—the rain, the springs, the brook; they have done it all, even as they are doing it this day.

But is not that still a hasty assumption? May not their denuding power have been far greater in old times than now?

Why should it? Because there was more rain then than now? That he must put out of court; there is no evidence of it whatsoever.

Because the land was more friable originally? Well, there is a great deal to be said for that. The experience of every countryman tells him that bare or fallow land is more easily washed away than land under vegetation. And no doubt, when these gravels and sands rose from the sea, they were barren for hundreds of years. He has some measure of the time required, because he can tell roughly how long it takes for sands and shingles left by the sea to become covered with vegetation. But he must allow that the friability of the land must have been originally much greater than now, for hundreds of years.

But again, does that fact really cut off any great space of time from his hundreds of thousands of years? For when the land first rose from the sea, that glen was not there. Some slight bay or bend in the shore determined its site. That stream was not there. It was split up into a million little springs, oozing side by side from the shore, and having each a very minute denuding power, which kept continually increasing by combination as the glen ate its way inwards, and the rainfall drained by all these little springs was collected into the one central stream. So that when the ground being bare was most liable to be denuded, the water was least able to do it; and as the denuding power of the water increased, the land, being covered with vegetation, became more and more able to resist it. All this he has seen, going on at the present day in the similar gullies worn in the soft strata of the South Hampshire coast; especially round Bournemouth.

So the two disturbing elements in the calculation may be fairly set off against each other, as making a difference of only a few thousands or tens of thousands of years either way; and the age of the glen may fairly be, if not a million years, yet such a length of years as mankind still speak of with bated breath, as if forsooth it would do them some harm.

I trust that every scientific man in this room will agree with me, that the imaginary squire or ploughman would have been conducting his investigation strictly according to the laws of the Baconian philosophy. You will remark, meanwhile, that he has not used a single scientific term, or referred to a single scientific investigation; and has observed nothing and thought nothing, which might not have been observed and thought by any one who chose to use his common sense, and not to be afraid.

But because he has come round, after all this further investigation, to something very like his first conclusion, was all that further investigation useless? No—a thousand times, no. It is this very verification of hypotheses which makes the sound ones safe, and destroys the unsound. It is this struggle with all sorts of superstitions which makes science strong and sure, and her march irresistible, winning ground slowly, but never receding from it. It is this buffeting of adversity which compels her not to rest dangerously upon the shallow sand of first guesses, and single observations; but to strike her roots down, deep, wide, and interlaced, into the solid ground of actual facts.