Jan. 2, 1890] 



NATURE 



205 



EFFECT OF OIL ON DISTURBED WATER. 



GENERALLY speaking, proverbs are the resultant 

 expression of observed facts, but the efficacy of 

 oil upon troubled waters would appear to be a proverb 

 which, instead of being preceded by and founded upon 

 trial and experiment, has rather led to the scientific de- 

 monstration and establishment of the truth it asserts. 

 From the very earliest ages the effect of oil when poured 

 upon disturbed water appears to have been widely known. 

 Aristotle mentions it, and accounts for the phenomenon 

 by assuming that the thin film of oleaginous matter into 

 which oil resolves itself when poured upon water pre- 

 vents the wind from obtaining a hold upon the water, 

 and so checks the wave formations which are the usual 

 results of wind at sea. Pliny, too, observes that among 

 the officers of his fleet the soothing influence of oil was 

 matter of common knowledge, and that the Assyrian 

 divers were in the habit of sprinkling the surface water 

 with oil when they wished to smooth down ripples, and 

 so obtain a better light for prosecuting their work below. 

 Coming down to more recent times, the custom of oiling 

 the waves with a view to facilitate navigation would ap- 

 pear to have fallen into desuetude. Benjamin Franklin, 

 however, seems to have been led, from observing the 

 effect of pouring overboard some greasy water, to test 

 its potency in a thoroughly scientific manner, when on a 

 voyage across the Atlantic. Having experimented with 

 great success upon the surface of a pond near London, 

 he tested the effects of oil upon the sea itself. A 

 stormy day was chosen, and from a boat, some half a 

 mile from the beach at Portsmouth, oil was poured 

 upon the sea. The experiment met with a very small 

 share of success, for, while a greasy patch of water 

 was discernible right to the shore, the surf con- 

 tinued to break upon the beach with unabated vigour. 

 Subsequent and recent investigation has confirmed 

 Franklin's finding, and proved that the greatest benefit 

 derived from the use of oil is obtainable in deep water, 

 where wave-motion is merely undulatory. When a shore- 

 approaching wave ceases to find enough depth to impart 

 to its neighbour its peculiar undulatory motion, it is no 

 longer a wave pure and simple, but becomes an actual 

 moving body of water which moves rapidly forward, 

 until it breaks with great violence upon the shore ; upon 

 such waves as these, oil has little or no effect. 



The knowledge of the influence of oil upon a rough sea 

 has long been known to those engaged in the whale and 

 seal fisheries, and its application is of common occurrence. 

 When their vessels or boats are overtaken by a storm, 

 they usually, by means of a drogue or sea anchor, make 

 what is nauticafly termed a dead drift, i.e. they suffer 

 themselves to be slowly drifted before the wind. In such 

 circumstances as these, the application of oil to the waves 

 insures that the area into which the boat drifts is one of 

 calni; as the oil spreads more rapidly than the boat 

 moves, and consequently prepares a smooth patch for 

 the vessel to drift into. If the captain, however, prefers 

 to run his vessel before the wind, then she ranges ahead 

 of the oiled patch, and thus the effect of oiling the waves 

 is very materially discounted. 



The native Eskimo, when engaged in transporting 

 his family from place to place, always insures a smooth 

 passage for the oomialc, or women's boat, by trailing a 

 punctured skin filled with oil from the stern of his kayak, 

 which he propels at some considerable distance ahead of 

 the boat containing his wife and children. 



Within the last twenty years many well-authenticated 

 instances have been placed on record as to the potency 

 of oil as a water-soother, but unfortunately the value of 

 such reports is very much diminished by the ship-masters 

 neglecting to explain the relative position of their vessel 

 in regard to the wind and sea. The British warship 

 Swiftsicre, when on a voyage from Honolulu to Esqui- 



mault, encountered a gale accompanied by tremendous 

 seas. A bag, punctured with the point of a knife, was 

 filled with oil and rigged out on the weather side of the 

 vessel. This had such a marked effect, that the vessel 

 rode bravely through the gale, and reached her destina- 

 tion in perfect safety. On October 8, 1880, a Mr. Fonda- 

 caro left Monte Video for Naples in a three-ton boat. 

 He arrived at Malaga on February 4, 1881. On his 

 voyage across the Atlantic, he had repeatedly to lay-to 

 during stress of weather, and reports that he considered 

 his safe arrival entirely due to his use of oil. A gallon of 

 olive-oil would last him, when hove-to, for twenty-four 

 hours. He gives it as his experience that oil does not 

 diminish the size of the waves, but renders them compara- 

 tively harmless by preventing their breaking. There is 

 a consensus of opinion among those who have tested 

 the use of oil, that a small quantity is quite as efficacious 

 as a larger one, a consumption of one pint per hour 

 being sufficient. Small as this quantity is, the ex- 

 treme expansibility of oil when floating upon the water 

 renders it quite adequate. Thus a ship running 10 knots 

 an hour will leave behind her a wake some 10 knots by 

 40 feet, covered with a thin film of oil. 



The Dunkirk Chamber of Commerce, fully alive to 

 the vast importance of the use of oil as materially con- 

 ducing to safe navigation, have just reported on the 

 results of some tests made at their direction among 

 the French fishing fleet off Iceland. One master reports 

 that by its use he was enabled to ride out successfully a 

 prolonged and severe spell of bad weather, which com- 

 pelled his confreres to run to port until the weather 

 moderated. The Chamber rewarded him with 100 francs. 

 Other captains who have reported in detail the result of 

 their experiments, agree with him in stating that, for 

 small vessels experiencing stress of weather in deep 

 water, the use of oil cannot be too highly recom- 

 mended. 



Nor is the utility of oil confined alone to this branch 

 of marine navigation. Advices just received from New 

 York furnish some interesting particulars relative to the 

 towage of the disabled steamship Italia of the Ham- 

 burg American Company. The Italia broke her shaft 

 whilst proceeding from Havre to New York:. In this 

 condition she was taken in tow by the Gellert, of the 

 same company. The towing hawsers — 6-inch steel wire — 

 were lengthened by heavy chain cables until the distance 

 between the two vessels was increased to 1000 feet. 

 Unfortunately, a heavy gale from the north-west caused 

 a dangerous sea to arise, and it was feared that 

 the Italia would have to be abandoned. As a last 

 resort, a can of oil with a small hole in the bottom was 

 set over the stern of the Gellert. The effect, according to 

 the master. Captain Kampf, was magical. The seas broke 

 over the bows of the Italia with much less fury, merely 

 surging past in a heavy swell, while the tension on the 

 cable was immediately relieved, and the Gellert was 

 enabled, in spite of continued bad weather, to reach New 

 York in safety, having towed her charge continuously for 

 the distance of 750 miles. Possibly many cases of aban- 

 doned towages in bad weather might be averted did the 

 masters of tugs but try the effect of a little oil prior to 

 casting the vessel adrift. 



The true part played by this oleaginous film iij 

 diminishing the disturbance of the sea seems to be that of 

 a lubricant. Waves are formed by the friction of wind 

 and water. Any force, therefore, that tends to lessen the 

 friction reduces the violence of the waves. As far as is 

 at present known, animal or the heavier vegetable oils 

 form the best lubricant between the two elements. 

 Mineral or fossil oils, which possess less viscosity and 

 are less oleaginous in their mechanical properties, exert 

 much less influence upon the water. This anti-frictional 

 force of oil can hardly be over-estimated. The Atlantic 

 waves have been calculated to exert an average pressure 



