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: | ) 24 MARINE REVIEW. [May 22 the United States during that year, as disclosed by the census returns. The undocumented tonnage consists of a class of shipping which is much _ lighter, more frail, and more short-lived, so that it is reasonable to believe that the annual loss in this tonnage fully equals that in the documented. Therefore, there is an annual demand, merely to make good average losses, for new tonnage aggregating between 300,000 and 350,000 tons, so that losses alone in our.national shipping create a steady demand for what may be regarded as a substantial annual total of new tonnage--more than one-half, probably, of the tonnage constructed during the year 1900. "Although iron ships were constructed in American ship yards pre- vious to the inauguration of the new navy, which were almost wholly em- ployed in domestic trade, modern steel ship building is contemporaneous with the growth of the new navy, the first vessels for which were launched about sixteen years ago. These initial constructions led to the equipment of a few of the ship building establishments in operation at that time with plants edequate for the production of modern ships of war, and these plants, with others that have been established since, are equally capable of producing steel merchant vessels of the highest type, a limited number of which, in every way a credit to the skill of the ship builders, have been turned out during the last decade." FLUCTUATION OF WATER LEVEL ON LAKE ERIE. Mr. Alfred J. Henry, professor of meteorology, has prepared under the direction of Willis L. Moore, chief of the United States weather bureau, a pamphlet upon the subject "Wind Velocity and Fluctuations of Water Level on Lake Erie.' Considerable information of a general char- acter regarding the lake is contained in the pamphlet. The total area of the lake is about 10,000 square miles. The contour of its bottom is such that for convenience of description it may be divided into three basins, namely, western, main and castern. The western basin has an area of about 1,200 square miles and comprises all that portion west of the islands. The bed of this basin is comparatively level and the average depth of water is about 30 ft. The main or middle basin has an area of about 6,700 square miles and comprises that portion of the lake between the islands on the west and the narrows between Long point and Erie on the east. The main basin has a shelving bottom, the depth increasing gradually to about - 80 ft. The eastern basin has an area of about 2,100 square miles and com- prises that portion of the lake east of the narrows. The greatest depth in the lake, 180 ft., is found in this basin off Long point. Mr. Henry says: "The prevailing winds on Lake Erie are westerly, the proportion vary- ing somewhat with the season of the year. At Detroit, near the western end of the lake, 69 per cent. of the winds are from a westerly quarter; at Cleveland, on the south shore and near the middle of the lake, 43 per cent. are from a westerly quarter, while at Buffalo, on the eastern end, 61 per cent. are from a westerly quarter. The resultant winds for each month of the year are given in the table below. RESULTANT WIND DIRECTIONS AT STATIONS ALONG LAKE ERIE, BASED ON RECORDS OF FIFTEEN YEARS. Stations. Jan. Feb. March. April. May. June. J uly. Detroit 08 ea css. S. 67 W.| S. 80 W. |N. 60 W. IN. 9 W. |S. 43 W.| S. 35 W |S. 67 W. Toledo ci2siccescess< 8.51 W.|S.57 W. |N.81 W. |N. 79 W. |S. 61 W.| 8.40 W.|S. 64 W. Cleveland. ..-..c.s.c:- S.33 W.|S.41 W.|S.78 W. |N. 10 W. | N. 79 BE. | 8.38 BE. | 8.16 EB. PTO ees oar shaves S.46 W.|S. 60 W.| 8.82 W.|S. 84 W.|S.57 W.| S. 44 W.| 8.70 W. Butta... 5.5 sicccesss 8.57 W.|S.54 W.| 8.72 W.|S.53 W. | i5.49 W.| S.44 W.| S. 58 W. Stations. Aug. Sept. Oct. Nov. Dec Annual DetrOibl siecle: S.60 W.|S.70 W.|S. 69 W.!1S.75 W.! 8.73 W. OLED scstiae sass §. 35 W.|8.40 W.|8.52 W.|S.51 W. |S. 57 W. Cleveland §.30 EH. | 3: 7 BE. 18.27 W. 18.35 W.|S.16 W. BNO re sicces 5.13 W.|S. 27 W.|S. 46 W.| 8.47 W.1/ 5S. 48 W. Bato ise S.52 W.| 8.62 W.|S. 73 W.|S.74 W.|S. 57 W. "From the above table it may be seen that the winds on the south shore east of Cleveland show less variation from a westerly quarter throughout the year than elsewhere on the lake. On the western end of the lake southerly winds prevail in winter, shifting to westerly and north- westerly with the advance of spring and back to west and southwest in summer. At Cleveland the prevailing winds appear to box the compass during the twelve months, being southerly in January, westerly in Feb- ruary and March, northerly and northeasterly in April, southeasterly in May and June, variable in July, southeasterly in August, September and October, and southwesterly in December. The unusually large number of southeasterly winds at this station is not clearly understood, unless, as suggested by Local Forecast Official Kenealy of Cleveland they are due to land and lake breezes, While the prevalence of lake breezes in the warm season would account for a large number of southeast winds, it should be remembered that frequently brisk to high southeast winds are observed at Cleveland, while at other lake stations the winds are southerly. "The frictional action of the wind on the surface of a body of water is manifested in various ways. First, a surface current is produced in the direction in which the wind blows. Second, it piles up the water on the shore which is directly opposed to the flow of the current and in the case of lakes and other landlocked bodies of water depresses the level of the water on the weather shore. Third, it alters the temperature of the surface waters both by mixture and the importation of waters having different temperatures. Of these effects the first named is by far the most impor- tant. On land, the frictional action of the wind, owing to the fixed and more or less rigid character of the objects interposed in its path, is scarcely appreciable, but when a wind of moderate force blows over a mobile surface for days and days--always in the same, or nearly the same direction, as in the region of the trade winds--a current is produced and maintained so long as the wind continues to blow. "Surface currents are also produced in the ocean in regions where the . prevailing winds largely outnumber those from any other quarter, as, for. example, in the North Atlantic, where the prevailing winds are westerly. 'Currents so produced are frequently interrupted, since fhe surface 'waters quickly respond to a change in the direction of the wind, yet the general drift of the water must always follow that of the wind for the same period. "The currents of the great lakes produced by the winds are feeble in ees comparison with those of the ocean. -The area of water surface exposed to wind action is relatively small as compared with that of the land, and in consequence of the greater frictional resistance of the land the velocity acquired by the wind in the lake region, though higher than in many parts of the United States, is still considerably below that which prevails over the ocean. : "The water that is transported by the winds from one end of the lake to the other can not return as a surface current, since the force which urges it forward naturally operates to prevent its return. The surface water that is drifted eastward across the Atlantic between latitudes 30° and 50° north and banked up against the continent of Europe, unlike the lake waters, escapes in three ways, viz, downward and to the northward and southward. In the case of Lakes Superior, Erie and Ontario, which are so situated with regard to the prevailing winds that easterly surface currents must prevail, there is probably a small volume of water, in excess of the normal flow, brought to the eastern ends of the lakes by the winds. This water, which ordinarily can not be of great volume, is usually dis- posed of through the natural outlets. When, however, strong westerly gales prevail the volume of water piled up at the eastern end of the lakes is generally so great that it can not be carried off by the river outlets, nor can it return as a surface current; it must, therefore, escape downward and westward as a return current beneath the surface. "The disturbances of level on Lake Erie, on account of the shallow- ness of the water at both ends of the lake, constitute at times a serious menace to navigation. The United States engineer corps, in charge of the survey and improvement of the great lakes, has maintained for many years a system of tridaily eye observations of the level of the water of the several lakes. During quite recent years automatic gauges have been put in operation on Lake Erie and also on the connecting rivers between Lakes Huron and Erie. The surface of the lake is never in absolute re- pose. The effect of a light breeze is to disturb the smooth surface of the water and to produce minute waves or corrugations in the surface film which disappear immediately upon the removal of the disturbing cause. As the velocity of the wind increases, small waves are produced uniformly over the surface of the water. If now the whole surface of the lake be subjected to a wind blowing uniformly in the direction of its longer axis the surface waters will be pushed along in the direction of the wind, as shown by Sir John Murray in his observations of temperature in the Scottish lochs. It is extremely doubtful, however, owing to the great length of Lake Erie, whether water is actually transferred from one end to the other, but there can be no doubt of the fact that, under the influence of strong winds, the particles of water have a motion of translation and effect a permanent change of place. - "It seems probable that the first effect of a strong wind upon the waters of the lake is to transfer from one end toward the other sufficient water to disturb the condition of hydrostatic equilibrium which existed before the wind began. Shortly after the maximum force of the wind has been exerted the lake tends to return to a state of stable equilibrium. The water that has been piled up on the leeward shore of the lake will imme- diately recede, although the velocity of the wind may continue high for several hours after the water falls. A condition of stable equilibrium is reached by a series of rockings of the water of the whole lake about a nodal line passing through the center of the lake, the water at either end rising and falling alternately until a condition of rest is attained. As a matter of fact the rockings do not continue uninterruptedly until the lake comes to rest, since the wind in the cold season generally becomes suffi- ciently strong a day or so after the storm has passed to overcome them. If, however, the winds are light the lake will continue to rock until equili- brium is restored." SHIP YARD NOTES. CC. & R. Poillon, Brooklyn, N. Y., are building a staunch steam pro- peller for James E. Ward & Co. of New York for service in Cuban waters. The timbers and other material entering into her construction are of first-class. Her keel is 12 by 12 in. oak; the frame is of oak and hacmatack 6 by 10 in., doubled, planked with 4 by 9 in. yellow pine to water line, with 3% in. above. The garboards are 4 by 15 in, oak; the ceiling of 3-in. yellow pine. She has two sister keelsons 8 by 12 each, bolted through, two rows of bilge keelsons 10 by 12 each, and two tiers of 4 by 12-in, clamps; the six thick strakes are 4 by 9 in. each. She will be fastened with com- position, galvanized and locust fastenings. Her deck is to be in keeping with the rest of her build, the main beams being 12 by 12 and the interme- diate ones 6 by 12 in. each; the deck will be of 3 by 5 in. white pine. Her deck erections will consist of deck house for galley, engine room and off- cers' quarters, and on the upper deck will be placed the pilot house, cap- tain's room, saloon and passenger accommodations. The steamer will have good freight room on deck and will be fitted with a strong derrick mast. She will have a compound engine furnished by John W., Sullivan of New York, and steam will be supplied by a Scotch boiler. The steamer Gen, Putnam was launched from the ship yard of the Pusey & Jones Co., Wilmington, Del., last week. She is a steel hull, screw steamer and will be used in the passenger and freight business be- tween New York and Greenwich, Conn. Her dimensions are: Length, 130 ft.; beam, 30 ft.; depth, 9 ft. She has an inverted, direct-acting, com- pound engine with cylinders 14 and 26 in. in diameter and 22 in, stroke. The new steamship Ransom B. Fuller for the Eastern Steamship Co. was launched from the yard of the New England Ship Building Co., Bath, Me., last Saturday. The Fuller is a three-decker, 300 ft. long, 39 ft. beam, 14 ft. deep and 8% ft. draught. She will have sleeping accommodations for 750 passengers, The! United Engineering Works of San Francisco has lately received an order for a steel steamer 162 ft. long, to be used on the coast as a lum- ber carrier. She will be equipped with oil burning apparatus and use oil for fuel. They have also under construction a tug boat 70 ft. in length for general service. : » At Dickey's Ship Yard, Alameda, Cal., work has been begun on the hull of the new wooden steam schooner which is to ply on thé Pollard Steamship Co.'s line between San Francisco and Gray's 'Harbor... She will measure 160 ft. in length, 36 ft. beam and 12 ft. 6 in, deep. ° Her cattry- ing capacity; will be 600,000 ft. of lumber. os a