Who can explain why there is nine hours’ ebb on the easterly shore of Portland and only three hours’ flow? It is a monkey trick, designed to prevent the poor sailorman from sneaking in just under the Bill: it gives him only three hours out of the twelve in which to do it, with Scylla on his left, and that most abominable howling Charybdis called Portland Race on his right. And if he comes up to the Bill at the end of his three hours’ limit, he has his heart in his mouth for fear that he should find the ebb stream catching his bows the moment he is round the Bill, and driving him headlong into the heart of the Race.
And what about the double tide of the Wight and Poole, the “gulder,” as they call it—the mystery of the Dorset and the Hampshire seas? In the days of my innocence I used to believe what I was told: that the double tide in Southampton Water was due to the water coming in first through the Needles channel and then around by Spithead later. It sounded reasonable for Southampton Water. But when I first made Poole, and found that they had a double tide there as well—and even out beyond Saint Alban’s Head—my philosophy was shaken, and my scheme of things fell heavily to the ground. Why on earth should there be a double tide on that coast? Who could explain it?
The enormous tide at the end of the funnel of the Bristol Channel is reasonable enough, though it is a little odd that it should be so very much bigger at Chepstow than at Gloucester. But how will you account for the prodigious heave at Saint Malo? Why does the flood come up Arun River like a racehorse recently invigorated with a bucket of beer, and at Newhaven hardly move at all up the Ouse?
I have stood outside the old piers at Newhaven in a little boat, with a northerly wind, expecting the first of the flood to help me to beat up, and waited for the quarter flood, and the half flood, and, later than that, and still have seen the sluggish surface water running out to sea against all the tidal laws that were ever written down: running out to sea, though the level of it steadily rose.
But there is no end to the mystery of the tides. Why is there a tide at Venice? It is not much of a thing, but it is there. And, for that matter, there is a tide in the Lake of Geneva. Here, again, the learned come barging in and tell us all about it. Closed basins (they say) like the Adriatic, even quite small ones, like the Lake of Geneva, have their little tides after the fashion of water swung in a basin. The explanation is given in some simile like this: “If you shake a basin slightly, the water will begin to swing with a regular movement back and forth.” So it will. But who shakes the Lake of Geneva? Or who catches the Adriatic at either end, and gives it a regular balance up and down, exactly so often, every so many hours?
All this questioning sounds like the Book of Job; but, note you, that I, for my part, am with Job, and against the scientists. For Job, or God, or whoever it was who set the catechism, put the questions and was careful to avoid the answers, and for my part I will do the same, not only in the matter of the tides, but for the whole basketful of things on which the scientists have been pontificating with increasing uppishness for the last two hundred years, until at last they have led us to the morass wherein we are sinking. When they pontificate on tides it does no great harm, for the sailorman cares nothing for their theories, but goes by real knowledge, and I by my sworn authority, the Admiralty texts, the like of which for excellence the world has not: “High water, full and change, six hours, thirteen minutes after Dover. The stream is barely perceptible in the first three hours of the flood, but runs very strongly in the third, and through three quarters of the fourth hour; after which it slackens. There is no perceptible stream in the last two hours of the flood.” Or again: “On rounding the Devil’s Point the tide is lost.” There is no theorising, no mumbo-jumbo. The thing itself, reality, is stated; and it is true. There is not even a passing wonderment as to where the tide goes to when it is lost. The Channel Pilot tells you the truth. You stick blindly to its text and you are saved.
There are many parts of the sea where the tide goes round like a clock, and no one can tell you why. Instead of the stream setting first east, let us say, with the flood and then west with the ebb, it goes all round the compass. It sets northwest with the beginning of the flood, then north, then northeast, then east, and so on, looking all round about itself like a performing dog, and slowly and ceaselessly revolving. It behaves not like an eddy, but like spokes. It is perfectly incomprehensible.
There is also this about the tides, which we all know to be true, and which we can see at work any day, but which I defy any man to rationalize: when the tide runs up a narrow river—or, indeed, any river—it will be still running up, say, ten miles from the mouth, when it is running down again, say, five miles from the mouth. What happens in between? Slack water, of course. But how is there slack water? How can the running down be going on at one point and, immediately beyond, the running up, without a division?
