Page:All the Year Round - Series 2 - Volume 1.djvu/210

 which had evidently oil upon it. Later information brought to light the fact that a brig had started shortly before with a cargo of cocoa-nut oil; some of the casks having been stove in by accident, the wasted oil was pumped out of the hold into the sea. The ships were two hundred miles apart, and yet the oily film reached from the one to the other. About ten or a dozen years ago a screw steamer, laden with corn, started from Copenhagen, to bend round the north of Jutland into the German Ocean. Just as she was coming near a stormy headland, the sea became very bad; the steamer shipped much water, the engine fires were gradually extinguished, the engines ceased to work, and the poor ship rolled helplessly on the water. A schooner was descried some few miles distant; and it was resolved that all hands should take to the boats, and pull from the steamer to the schooner. The crew poured some oil on the waves as they went, and were thus enabled to meet a somewhat less troubled sea than would otherwise have encountered them.

It seems to be now pretty well known how and why the oil acts in this friendly way: although some parts of the phenomenon still remain obscure. If it be attempted to raise waves upon the surface of oil in a vessel by the force of the wind, it will be found very difficult to succeed. The difficulty is probably due to the mutual cohesion among the particles of oil; there may be also less attraction between air and oil than between air and water. The effect is obviously far more physical than chemical. Dr. Franklin expressed his opinion that air is gradually frustrated, by the oil, in disturbing the tranquillity of water. First the wind, blowing over the water, rubs against the surface and raises it into wrinkles; then, the wind continuing, those wrinkles become the cause of little waves, and the little waves of greater waves, and so on until strong billows are the eventual result—produced not necessarily by a violent wind, for a moderate wind will do it if continuous. Such is the case under ordinary circumstances; but now for the oil. As a drop of oil spreads into a large and wonderfully thin film on the surface of water, there must be some kind of repulsion at work among its particles; but be this as it may, the thin film presents no points or roughnesses against which the wind may catch, no little file-teeth or saw-teeth to produce a wrinkle. The oil moves a little with the wind, acting as a sort of slide by the aid of which the air glides over the water. With a strong wind, every large wave becomes covered with a kind of rippled armour of small waves or wrinkles; and each of these wrinkles gives a hold by which the wind may further act; but if there be a film of oil on the surface, these small wrinkles are prevented from forming, although the large waves remain. What is done is, not to prevent large waves from rolling and heaving, but to arrest their increase by new waves formed on the back of them. What occurred to the boats off the coast of Denmark shows pretty clearly how the prevention is brought about. Two boats were supplied with five gallons of oil each. While the men were tugging at the oars, the captain, in one of the boats, watched the advance of the waves, and at an opportune moment, when a sea appeared about to approach and swamp them, he caused a gill or half a pint of oil to be poured out of the can; the effect was as if the wave divided and fell off on either side of the boat. The captain economised his oil in the long boat so as to make it last well out till he reached the schooner; the mate in the lifeboat was a little too lavish, got rid of his oil too soon, and had to pull the latter part of the voyage against a very heavy sea.

Working men in some trades know a little of this oil subject, though not in connexion with waves. If a solution of sugar, or any one among a considerable number of other solutions, be boiling in an open vessel over the fire, and be in danger of boiling over, a little oil poured upon the surface will immediately make the violent bubbles subside. Still more simply, if we draw a mark with a piece of soap, round the interior of a vessel somewhere between the top of the vessel and the level of the boiling liquid, the oil in the soap forms a kind of magic ring, which prevents, or at least, retards, the rise of the ebullition above that point. Noxious and unhealthy vapours may to some extent be kept from rising by some such means.

have possibly heard the story of a foolish man who was so highly delighted with the performance of Punch in an itinerant show, that he immediately purchased the puppet at an exorbitant price, and took it home for his own private amusement. Likewise you have heard, or if not you have conjectured, that when the foolish man placed Punch on the table, and found him incapable of movement, he felt grievously disappointed.

But now I am going to tell you of something of which you certainly have not heard.

I am the foolish man.

My disappointment, as you have heard, or conjectured, was excessive. Without writing my autobiography, it will be sufficient if I come at once to the fact, that at the time of my absurd purchase, a varied and indiscriminate love of amusement had converted me into a sort of Sir Charles Coldstream. The notion of Punch jumping on the table for my sole entertainment, had brought with it a sense of refined selfishness that was almost overpowering. I recollect I once saw Mr. Macready's inimitable performance of Luke in the version of Massinger's City Madam, entitled Riches. Luke, a prodigal who had wasted his substance, and had afterwards, through the supposed death of his brother, become possessed of immense wealth, sat at the head of an enormous table, groaning with every sort of wine and viand, and he sat—alone. Here was a repast