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the whole system hangs together and is under one man.” In Spain the administration is similarly organized; in Denmark, Sweden, Norway, Holland and Austria, the service is under the Ministry of Marine.

in the United States, Russia, Hanover and Hamburg, there are central boards of superintendence, constituted with special reference to the duties on hand. Even in Turkey, the service was conceived to be under the Admiralty, though the Ottoman “ department" was “at a loss to furnish information."

However, we are not prepared to say that very much is provided by this array of contrasts, or by arguments to which most of our institutions would be exposed in a similar degree. We have our own way of doing things, and our way is not remarkable for simplicity or system. We are all for “self-government" and all against “centralization.' We have a natural antipathy to “ Boards” and we are in the habit of looking rather to results than to means. In short, if the light-house service of the kingdom is efficiently administered, we would not be likely to care much about the methods by which efficiency was attained. That would be the point, beyond doubt, on which opinion would turn, and here it is impossible to avoid remarking that the actual condition of our coast lights, as described by the commissioners, is really superior to any thing that could be expected after the description of the management. Complex and illorganized as our system may appear, the result cannot be termed discreditable to us. The report frankly admits that Great Britain is better lighted than any other country except France, and nearly as that. The French, it must be remembered, had an immense advantage in commencing with a carte blanche only thirty or forty years ago, while we have a system which is the growth of ten generations. No doubt, the contrast is striking, and the effect, unluckily, is visible at very conspicuous points. The commissioners tell us that the harbor lights at Dover, Folkestone and New-haven “present a singular variety of faults, comprising among them nearly all those which can be committed in light-house arrangements.” No sooner, however, does the British tourist leave his own shores than he comes at once at Calais, Boulogne or Dieppe, "to small but brilliant harbor lights, which are all dioptric, and in the construction and management of which there are displayed all the achievements of the science of illumination.” Of course this is rather aggravating; but much the same may be said of a dozen other usages on the two sides of the channel. We are English, and our neighbors are French. In saying that we have said nearly all, and what is more, we doubt if any novelties of management will enable us altogether to unsay it. Many of our light-houses are admirably kept—the Scottish lights particularly, and the floating lights everywhere. In some respects we are even ahead of the French, for we supply our light-keepers with books and medicine-chests, whereas the French show no such consideration for their servants.

Still there is evidently room for reform. Much of the praise bestowed by the commissioners has been earned by the general authorities exclusively, the performances of the local authorities, with a few honorable exceptions, being greatly inferior. The evils, too, arising from want of uniformity, are truly serious. A danger signal in one place means safety in another. The system of buoyage varies everywhere; it is one thing in the port of Liverpool, and exactly the opposite thing in the port of Dublin. Even colors and flags do not always tell the same story, and of local

lights, buoys and beacons together, it is generally affirmed that they are managed on independent systems, without any uniformity, and with but indifferent results. After what we have said, the main features of the commissioners' proposals will probably be anticipated. They recommend the formation of a central Board, with a scientific staff. They consult the interest of existing bodies, by vesting the elections of certain of the new managers in the hands of the old authorities, with the reserve of a place to be filled by government, and they retain even an antiquity of title in styling the new board the “ Trinity Commissioners for Lights. After adding four official members, they would connect the board for purposes of parliamentary responsibility, either with the Board of Trade or the Admiralty, and they conclude with a natural anticipation that their suggestions may result in an improvement of our light-house administration and increased security to the navigators of British waters. All this we place before the public as

is given.

The discussion of the proposed scheme will follow soon enough, and we will only add, therefore, that in our opinion the results of this very thorough inquiry, though they have brought many defects to light, and suggested many reforms, ought really to make us thankful that a system so unpromising in appearance could be worked with such respectable effect.

CONTRIBUTIONS TO NAUTICAL SCIENCE.

The eighth meeting of the Literary and Philosophical Society was held at the Royal Institution, in February last, the Rev. H. H. Higgins, President, in the chair.

A paper was then read by Dr. Dobson, head-master of the Conway, entitled “ Contributions to Nautical Science.Mr. Dobson said :-Of all men the sailor is most indebted to the mathematician, who has framed the rules which the sailor practices and relies upon; and computed the numerical data which the sailor takes from his nautical almanac, data which embody the practical results of mathematical problems of the very highest order of difficulty, and which have taxed the powers of the greatest mathematicians from Newton's time to our own. Nautical science, then, having thus been constructed by help of the higher mathematics, offers an ample field for simplification; and that such a process is most desirable, will be obvious when we reflect how essential a clear knowledge, both of the principles and practice of nautical science, is to that numerous and valuable body of men who are responsible for all the lives and property afloat. Such knowledge is more than ever indispensable in these days of steamships, clippers and rapid passages, when a merchant captain must strain every nerve, and, what is much worse, run every risk, in order to satisfy an exacting public, by making a passage in the shortest possible time. It is evident that the danger from an error in the reckoning of a dull-sailing vessel is much less than in that of a long, sharp clipper, on the principle, that the farther you go on the wrong road the more you go wrong. The first subject to which I shall ask your attention this evening is a question relating to practical navigation, and may be enunciated thus: “The direction of the wind and the course of the ship being known, required the direction of the sails, so that the ship

may make the most headway.” This problem belongs to the most difficult class of maxima and minima, which are most successfully attacked by means of the differential calculus, and thus I first accomplished its solution. But, anxious to bring it within the reach of my pupils, I reconsidered it, and succeeded in solving it by means of plain trigonometry, and at last was rewarded by discovering the simple geometrical proof which follows. I am not aware that this problem has been published in any form. It is certainly not mentioned in any of the numerous English and foreign works on navigation that I have consulted.

In some of the most important practical applications of nautical astronomy, where two altitudes of a heavenly body are taken at an interval of a few hours, during which the vessel has been proceeding on her course, it is necessary to reduce the first altitude to what it would have been if it had been measured at the place where the ship is when the second observation is made. My second contribution to nautical science is a simple elementary investigation of the value of the correction to be applied to the first altitude to compensate for the “run” of the ship, as it is called. This value, of course, is well known; but the proof is well adapted for instruction, inasmuch as it has the advantage of placing clearly before the student the things which he is required to reason about, and is made to depend upon the rule for parallel sailings, the simplest case in spherical trigonometry. In this case, as in several others, I had the alternative of either investing a simple intelligible proof, or of giving the rule to my pupils without demonstration, and resting on authority alone, a mode of proceeding altogether inconsistent with sound teaching. These “contributions” were each of them accompanied by their appropriate mathematical proof.

At the conclusion of the paper, the Rev. J. ROBBERDS made some remarks expressive of his gratification at the excellent and lucid style adopted by Mr. Dobson, which could not fail to be useful in the communication of information to his pupils.

LAUNCH OF THE STEAM RAM, DEFENCE. The steam ram, DEFENCE, was launched from the yard of Messrs. PALMER & Jarrow on the 24th of April, at Newcastle, England. The launch was of a most successful description; and the ship, as she floated to the other side of the river, was greeted by the enthusiastic plaudits of the assembled spectators and workmen. When fairly launched she drew about eighteen and one-half feet of water; and after the machinery is fitted up it is supposed that the draught will be nearly twenty feet. The next task was the removal of the vessel to the dock. A large cable chain unexpectedly giving way, however, the frigate suddenly grounded; and with all the efforts that could be employed, it was found impossible to get her off by that tide. The extreme length of the DEFENCE is two hundred and ninety-two feet; breadth from the beams, fifty-four feet; the extreme depth, thirty-eight feet two inches. She is 3,669 tons register, and has been pierced for twenty-eight guns. The engines possess six hundred horses' power, and the speed at which the frigate is reckoned to sail is at the rate of ten knots an hour. After the manner of the Great EASTERN, she is double-bottomed, and is iron-plated to the extent of one hundred

and seventy feet to two feet below the water-line. The bulkheads are covered by armor plates, which are furnished with plated doors of the same material

. She is further surrounded by wing passages in the inside on each side, the object of these being to enable the men on board to pass along to plug up any holes made by guns. The armor plates with which the vessel is cased are of various lengths, from thirteen feet to seventeen feet, by about three feet three inches wide and four and onehalf inches thick, and weigh from four to five tons each. Underneath the plates are eighteen inches of teak, beneath which lies the actual skin of of the ship. Strength and security seem to be the guiding mottoes by which the builders have been actuated. We consequently find that the armor plates have been bolted in with inch and a half bolts; and the edges have been “feathered and groved,” similar to the deals of a floor. On the fighting deck and in the bulkheads are two doors, by the passage afforded by which cannon can readily be transferred from one part of the vessel to another. At the stern the new frigate is strongly fortified by an elaborate process, being intended to act as a steam ram; and with a prominently projecting beak, the workmanship is so arranged that a hostile ship would be struck under the water-line and immediately sunk. The stern falls in at the head between five and six feet, in the shape of the rudder; and at midships is a kelson forty-four inches in thickness, which is carried right up to the stern, and is also of immense durability. The upper and main decks are of iron; the fighting decks being composed of oak of about six inches in thickness. The magazines are within the armor-coated portions of the ship, and below the water-line; and when finished it is expected that she will be able to carry twenty 100-pounder Armstrong guns.—Newcastle Daily Chronicle.—The DEFENCE was floated off on the 25th without having sustained any damage.

THE AMERICAN SHIP GREAT REPUBLIC. The GREAT REPUBLIC, said to be the largest sailing ship afloat, arrived in the Mersey on the 17th July from San Francisco, having made the passage in ninety-five days. She carries four masts, and she is 3,356 tons burthen. She has on board upwards of 3,000 tons of wheat, consigned to Messrs. Frederick Huth & Co., Chapel-street. The GREAT REPUBLIC is at present anchored off New-Brighton, but when the tide answers she will go into the Huskisson Dock to discharge her cargo. She is commanded by Captain LIMEBURNER.

NAMES OF THE NEW GUN - BOATS.

Indian names are to be given to the new gun-boats now building for the government. The boats building in Maine are to be named “KATAHDIN,” “ AROOSTook,” “Penobscot” and “Kineo." Those in Massachusetts, " MARBLEHEAD,” “SAGAMORE,” “Cuocura” and “Huron." In Connecticut, “Owasco," "KANAWHAT" and “ CAYUGA." In New-York, “UNADILLA,” “OTTAWA," Pembina,” “Seneca,” “ CHIPPEWA” and “Winona.” In Pennsylvania, “ItasCA,” “Scioto" and “WISSAHICKON.” In Delaware, "LAHOMA.” In Baltimore, " Pinola."

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THE MASTS OF THE WARRIOR. The masts, spars and other gear for the WARRIOR, iron naval steamer, have been put on board that vessel by the shipwrights sent from Woolwich dock-yard for that purpose. The main and foretopmasts are of large size and strength, each measuring sixty-five feet in length, and weighing rather more than three tons. The mizzen-topmast measures fifty feet, and its weight is about two tons. The fore and main-yards are each as large as the masts of many large ships, each measuring one hundred and five feet in length, and weighing upwards of six tons. The length of the mizzen-yard is seventy-one feet. The three topsail-yards are also of great size and strength, the two largest being each seventy-four feet long, and weighing about two tons. The whole of the masts, yards, &c., for the Warrior have been constructed of unusual strength, under the immediate superintendence of the officials connected with the masting departments at Chatham dock-yard.

The Warrior's chain cables, (two and three-eighths inch,) manufactured by Messrs. Lennox & Co., have been tested at Woolwich and bore the strain of one hundred and one tons, ordered by the Admiralty as the regulated test, well.

NEW LIGHT-HOUSES. Roman Rock Light.—- False Bay, Cape of Good Hope.—Official information has been received at the Light-House Board through the Department of State, from the Colonial Government at the Cape of Good Hope, under date of the 17th June last, that a light will be exhibited from the new light-house on the Roman Rocks on the 16th September, 1861, which will supersede that shown at the light-vessel now moored a cable's length north of the rocks. It will be a revolving white light, showing a bright face for the space of twelve seconds twice every minute, which will servé to distinguish it from the Cape Point light in thick weather, as that light revolves only once every minute. The light will be fifty-four feet above the sea, and visible in clear weather from a ship's deck thirteen miles distant.

The light-tower is forty-eight feet high, the lower half of which will be painted black and the upper half white. From the light-house, Noah's Ark bears S. 56° W. 7-10 miles, and the Dock-yard clock W. by N. 1.65 mile.

N.N.E.E., 2 cables from the light-house, lies the Castor Rock, with only fifteen feet on it at low water, springs; its position is marked by a beacon, with a flag having the word "rock" painted on it. There are patches of nineteen and twenty-four feet between the Castor Rock and the light-house, which renders it necessary for large ships to give the light-house a berth of at least three and a half cables, when passing to the N.E., before hauling in for Simon's Bay.

In sailing for Simon's Bay, by keeping the light-house in line with Elsey Peak, bearing N. & W., a ship will pass midway between the Whittle Rock and Miller's Point.

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