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228 ble the length of the longest vessel existing at the time of her design, represented a daring departure from this general principle of evolution; she was, in fact, created almost ab initia by the brain of man without any pre- vious experience of such a huge struc- ture for a guide, and her absolute suc- cess from a designer's point of view was a striking tribute to the inesti- mable value of applied scientific know- ledge in the design of ships. In the nature of things no such jump can ever occur again, but the very fact that British designers rea- lized more than fifty years ago the economy and general advantages to be obtained from the "big ship" is something of which we may well feel proud. It is interesting to recall that for many years prior to 1899, when the Oceanic was completed, the latest big ships were frequently described as "the largest in the world with the exception of the Great Eastern." Striking Differences The most important point to be de- duced from the comparison of the two groups of ships refrred to is that dur- ing the centuries of evolution of the wooden ship the maximum length attained was 275 ft., whereas the iron or steel ship has evolved from about 320 ft. to nearly 1,000 ft. in less than three-quarters of a century. The rea- son for this striking difference is not very far to seek. In the first place our knowledge of the stresses and strains experienced by ships has been greatly extended since the introduc- tion of iron and steel for ship build- ing, and, secondly, wood as a mater- ial- for construction rendered it im- possible to obtain sufficient longitudi- nal strength for the great modern vessels that can be built of steel. In this latter connection, it may be re- marked that the bogging and sagging stresses which are the most impor- tant to be considered in ship design cause an amount of deformation (in the length of the vessel) which can be measured in inches or fractions of an inch in steel vessels, whereas the cor- responding deformation in the old wooden ships was often a matter of feet. The first point to be noticed, therefore, in connection with the ques- tion of the size of ships is that of the nature of the materials of construc-' tion. Steel is an ideal material for many reasons, among them may be mentioned: a, Cheapness. b. Iron ore is widely scattered over the earth's surface. _¢, Ease of working. THE MARINE REVIEW d. Mechanical properties and dura- bility. Gross : tonnage. Engines. 8,100 Reciprocating. 10,000 Reciprocating twin-screws. 17,000 Reciprocating twin-screws. 24.000 Reciprocating twin-screws. 32,000 Turbines, four screws. ; 5 : Combined turbines and reciprocating 45,000 b 50,000 Turbines, four screws. 47,000 Turbines, four screws. In b and d are to be found two rea- sons why it is highly improbable that any other material is ever likely to supersede it--the thickness of the material of the shell required for the proper longitudinal strength of the ship closely approximates to the min- imum thickness that is necessary for stiffness to withstand local stresses such as water pressure, docking, etc., without an excessive amount of local stiffening. Should a new material be discovered in the future with a tensile strength, say, ten times that of steel in proportion to its weight, it will not enable the thickness of most por- tions of a vessel's structure to be reduced in anything like the same ratio, except in the highly improb- able event of its stiffness and elas- ticity also being ten times that of steel. Of course, slight improvements may be made, such as that claimed by the use of vanadium steel, but these would be slight only, and would have little bearing on the question of the limit of size of vessels. It may there- fore be safely prophesied that the limit of size will not be greatly af- fected, if at all, by the materials used in construction. Personal J. W. Isherwood, of London, in- ventor of the Isherwood system of ship construction, and James French, of New York, Lloyds chief surveyor for the United States, visited Cleve- land 'during the early part of June. Capt. John D. Patterson, of Atlanta, Ga., has been appointed general super- intendent: of the Panama railroad, vice J. A. Smith, resigned. A farewell ban- quet was given to Mr. Smith at Hotel Washington, Colon, on May 17. Em, 8. DeYoung, ot. the Johnson Lighterage Co., New York, has been elected a member of the Maritime Association of the Port of New Work. Benjamin F. Cresson, Jr., recently deputy commissioner of docks and ferries of the city of New York has been appointed engineer of the New Jersey harbor commission. ® Jj. Benner: and Capt. M.. M. Giannomi, of the Morse Dry Dock & Repair Co., New York, have been elected members of the Maritime As- sociation of the Port of New York. June, 1913 R. B. Wallace, general manager of the American Ship Building Co, sailed for Europe last month, accom. panied by Mrs. Wallace. M. W. Williams, representing the Tomlinson interests and the Berwind Fuel .€o., has removed to ° 1504-6 Rockefeller building, Cleveland. John A. McGregor, president of the Union Iron Works, San Francisco, vis- ited New York recently. The Mallory Line is inviting ten- ders for three. passenger steamers, 405 ft. in length. Charles W. Morse has been elected president of the Hudson Navigation Co., New York. Items of Interest The Vesta Coal Co., a subsidiary of the Jones & Laughlin Steel Co., Pittsburgh, launched its fifteenth 200- ft. steel barge, May 27. The Jones & Laughlin Co. is building two barges a month, approximately 10 months of the year, for the Vesta company and will continue to do so until the fleet e€onsists .of about 100°° barges. - "AL though twice as long as typical coal barges used on the rivers in the Pittsburgh district, the Vesta com- pany has found the larger type just as. practical and. .much..-more. 'satis- factory during the winter months. Each barge contains about 200 tons of steel. The new Pennsylvania ore dock in the outer harbor at Cleveland is now making fast time. The steamer E. Y. Townsend with 11,209 gross tons of ore was unloaded in 5 hours and 10 minutes, and the steamer W. P. Sny- der Jr., with 11,900 tons of ore, was unloaded in 5 hours 25 minutes on May 19. The Hamburg-American Line is making inquiry into the cost of con- structing, six steamers in American yards evidently to engage in coast- wise traffic and to take advantage of the remission of Panama canal tolls to ships of American register. The Lake Carriers' Association and the Great Lakes Protective Associa- tion have moved into the offices for- merly occupied by the _ Gilchrist Transportation Co. in the Rockefeller building, Cleveland, O. The steamers Socapa and Sahara, of the Tomlinson fleet, have been named G G. Barnum and Cuyler Adams, respectively, after men well known at the head of the lakes. The Great Lakes Dredge & Dock Co. were the lowest bidders for dredging at Superior Entry and at Portage harbor, Lake Superior. Si cm ihe ie Ad ae aaia