The Shipping and Mercantile Gazette recently called attention in a leading article to the advisability of the use of oil during rough weather at sea under certain favourable conditions. They remarked that it was gratifying to observe that the International Maritime Conference, which has recently terminated its sittings at Washington, has, after giving the subject the most careful attention, pronounced averdict in exact accord with our own expressed views on the matter. Two able articles -which have recently appeared on this subject, in the pages of Nature and Research respectively, also go to swell the concensus of opinion prevalent among scientists and practical navigators, that the efficacy of oil as a water-smoother is dependent to a great extent upon the concomitant circumstances of weather and depth of water. Given deep water, a | wave is simply an undulatory motion i caused by the friction between wind and water. Under these conditions the oil, which should be heavy and possessing strong oleaginous properties, acts as a lubricant between these two wave producing media, and BO materially checks wave action. In shoal water, however, a shore-approaching wave ceases to be a mere undulation, and becomes an actual moving mass of water, a wave of translation ; and this no quantity of oil can prevent from breaking upon the shore.

This is no new discovery, but, as the writer in Research points out, was the conclusion arrived at by Benjamin Franklin after a series of exhaustive experiments upon the subject. Subsequent investigation has confirmed the truth of Franklin's finding in every particular. Various nautical associations have given this subject their most careful consideration, with a view to furnishing practical directions to shipmasters as to the best methods of using oil in rough weather. The Dunkirk Chamber of Commerce a few months ago, with the intention of minimising the loss of life occurrent among the French fishing fleet off Iceland, inaugurated a system of awards to those captains who used oil during stress of weather, and reported accurately upon the effect produced. Our columns have often contained notices of oil being used by shipmasters during bad vreather, and we would be pleased to give prominence to any such reports that shipmasters may send us. But we would point out that if the account of the using ! of oil at sea is to be of the slightest assist- j ance to other navigators, the circumstances under which the oil was used must be stated most explicitly. That oil is bene-' ficial under some conditions, all will admit. What those conditions are, and ! the exact relationship existent between them, it is for the practical navigator to ! determine. The direction of the wind, the flow of the sea, the position and heading of the ship should be stated with the minutest accuracy, for without these data it is impossible to gauga the true value of the test. The towing of the disabled vessel Italia by her fellow liner the Gellert a distance of 750 miles through persistent bad weather affords another striking illustration of the benefits accruing from a judicious use of oil. As is aptly pointed out in Nature, many cases of abandoned 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. In effecting transhipments at sea, as in removing fish from the smacks to the carriers, in facilitating the launching of boats from distressed vessels, and in materially conducing to their subsequent safe navigation, oil has frequently been found simply invaluable. A knowledge of its wave-allayiag properties cannot, therefore, be too widely disseminated among the nautical fraternity. Further, it is so cheap, and such a small quantity suffices to produce the most adequate results, that oil should form a necessary part of all ships' stores, and an imperative adjunct to the life-saving equipment of all ships' boats. On account of its cheapness, the comparative ease with which it is applied, and the encouraging success which has in many cases attended its use, we earnestly recommend this watersmoother to the attention of all shipmasters.

A note should be made of the fact that vegetable or animal oils are the most desirable for the purpose—-mineral oil, especially if refined, producing but a very moderate amount of success. As we remarked last May, experts agree in the opinion that the most effective way of applying the oil is to facilitate its spreading to windward, and that the discharge of about two quarts per hour is amply sufficient to produce the desired result.

The fluid can be easily distributed by means of punctured canvas bags, or through the w.c. openings—any way, in fact, so long as the oil is kept constantly dripping slowly into the sea. We trust, also, that those who put its efficacy to the test will not fail to report in detail, for the benefit of their nautical confreres, the exact conditions under which the test was applied..