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spaced hold beams, and, quite common- ly, a double bottom. For smaller ves- sels the raised quarter-deck or well deck type, was practically supreme; but it seems unnecessary to deal with them separately, as they presented few special features in construction which have not since been embodied in the now par- amount type having continuous decks. The raised quarter-deck has been of ey- olutionary value from the fact that the demand for the omission of complete tiers of beams in way of the quarter deck had = to be faced and met almost from the beginning of that the introduction of web frames, as an efficient substitute for a third tier of beams in a three-deck, or a second tier in a two-deck ship, is now a matter of quite ancient history. The web frame ship was an improvement in design for bulk carriers, but the broken stowage for other trades created a demand which led to the deep-frame system being in- troduced, I believe, by Messrs, Stephen, of Linthouse, about 1887; that is, each -frame was made stiff enough and strong enough for the longer spans caused by the omission of tiers of beams, These systems have been grafted upon one which gradually increased the sizes of ordinary frames in rough proportion to the midship dimensions of the ship, and introduced additional tiers of beams at arbitrary depths, so that anomalies are not unknown in practice. The develop- ments in general design of the past 15 years, were the wider spacing of stanch- ions,.and the omission of the wood deck from the -- second-deck level, an omission of valueless material which seems to have been at first generally, although not universally, re- garded as one having such - structural importance as demanded either com- pensation or freeboard penalty. Thata wood second deck, cut by bulkheads and non-existent in the machinery space, could ever have been. regarded as an effective element in the structure of a steel ship is one of those mysteries which appear to attend all evolutions. The steamer Lincluden, 312 ft. by 42. 86 far. as: b> it; 43a. by" 26 16. 3'in.,, know the first real single-deck ship of this depth, or near it, was built by Messrs. Furniss, Withy and Co., West Hartlepool, in 1896, and was consid- ered to be a radical, if not a dangerous departure; but circumstances have more than justified the design, and this ship was the forerunner of a type which is now becoming comparatively common. A number of relatively large vessels have been built having wide-spaced strong beams in association with wide stringer plates at mid depth, but the largest ves- sels of ordinary form of which I know anything in which reliance is placed sole- ly upon deep framing, unsupported by "TAE. MarRINE. REVIEW beams of any kind below the upper deck, have depths of 28 ft. 6 in. to 29 ft. 6 in. The range of development in this type is shown by comparison of this vessel with a single-deck steamer, 252 ft. by 43 ft. 6 in. by 23 ft. 6 in., of which a number have been built for service on the Amer- ican lakes, and whose depth corresponds with the least for which three tiers of beams used to be the. standard. We have already reached a close approxima- tion in design to an open boat with a portable deck, and, if trade requirements demand it, we are yet far from having reached any limitation upon the dimen- sions of this type based on practical con- siderations. The evolution of the single- deck steamer from the three-deck type has been on clear, well-defined lines, but recently activity in designing new meth- ods of construction and types of ship in- tended to solve the problem of combin- ing large capacity and large deadweight on limited draught, with ample water ballast capacity, unbroken stowage, ab- sence of hand trimmings for bulk car- goes, and simplicity of construction, has produced designs which are such varia- tions from the parent ship.as to form dis- _ tinct species, and which have already had, in some cases, quite an evolutionary his- tory. For example, in Mr. M'Glashan's ship there is no change in external form, but by the simple expedient of adopting two skins of plating it is possible, not only to carry a very large quantity of water ballast, having a higher center of gravity than the normal, but to secure such great transverse and longitudinal strength from material disposed of in the best position as to give the power of practically in- definite expansion in ship dimensions. Mr. Foster-King then proceeded to de- scribe and illustrate different types of cargo vessels, such as Messrs. Doxford's turret, Messrs. Priestman's . self-trim- mer, Harrowing and Dixon's cantilever, and the Ropner trunk. In concluding, he said: If attacked solely from the point of view of economy and efficiency of de- sign and as a problem in engineering, unhampered by preconceived ideas of construction and trade requirements, it seems to be obvious that the natural de- sign of a ship-shaped girder would be one which would have the material dis- posed entirely on the circumscribing walls, but misconceptions of true principles in design are unavoidable legacies from pre- vious constructive methods. The influ- Ns which have caused persistence in bad disposition of longitudinal material are not easily understood, perhaps they follow from the influence of wood ship- building methods, while the retention of the name "main," as applied to a deck which was not the top deck, may have had the effect due to suggestion. We have certainly grown up amid the concep- tion that numerous tiers of beams are 19 natural, and that their omission de- mands compensation, instead of 'what seems to be the sound idea exemplified by Messrs. Brunel and Scott Russell half a century ago, that the ideal structtire would have the longitudinal material massed on the upper deck, bottom, and sides; the transverse members would be of the simplest form and fewest number possible, with their contributory ele- ments as far apart as the thickness of plating would permit; while additional tiers of beams or layers of plating would be regarded as unscientific and to be fit- ted only under compulsion of trade con- ditions, but that, when fitted, the best use had to be made of them as* factors in the structural equation, in order to minimize what must necessarily be wasteful in weight, just as the central core of a shaft or any other massing of material in the wrong place. It appears to me that the tendency of all types of development, with the exception of the large mail and passenger steamer, has been towards reduction in number of parts, economy of labor, rather than of weight, to a probably unconscious reali- zation of the principles of design which I have ventured to put forward as the best; and particularly in the case of bulk carriers to the closest possible approxi- 'mation to an open boat--a design which seems to be not only the child of the ages, but the father of the ideal oeiee for such -vessels. MODEL OF GJOA. A model of the 72-ft. sloop Gjoa, in which Capt. Roald Amundsen made the only trip ever negotiated through the Northwest Passage around the Amer- ican continent, was exhibited at the Maritime Exchange in New York re- cently. The model is eventually to go to the Smithsonian Institution at Washington. The original of the mod- el is an old sealing vessel of the Nor- wegian type, 35 years old, of 49» tons burden, and is 72 ft. over all. The model is three and a half. feet long and from the keel to the top of the mast it stands four feet. The orig- inal of the model now lies at the Mare Island: navy yard and it has been sug- gested that she be the first vessel to pass through the Panama canal, thus making her the first craft to round the North American continent. The steamer Calumet building for the Lackawanna Steamship Co. will be launched at the Wyandotte yard of the American Ship Building Co. on Saturday next. Capt. Walter Scott, for two years shore captain of the Graham & Mor- ton fleet, has been appointed harbor master for the port of Chicago.