Draught and Calculations of the Lake Propeller "Oriental."

The "Oriental" was built at Buffalo, in 1854, by Messrs. Bidwell and Banta, and is the largest screw vessel on the Lakes. She is of 950 tons register, and carries 750 tons of freight. The weight of engine, boiler, and 100 tons of coal, is equal to 208 tons. The loaded draught of water is 11 feet. Average speed when loaded is equal to 9 miles per hour in good weather, but she runs much faster and steers better when light.

The semi-circle described in the engraving of body-plan represents the periphery and position of the screw propeller as now fitted. The first screw was made 22 feet in diameter, but was impracticable for use -- the vessel refusing to steer. The present screw was found best adapted for propulsory purposes, having less diameter and pitch ; and no difficulty is now experienced in working ship. It will be observed that the dip of screw-blades is small (60 square feet immersed when loaded) in proportion to [p. 140] the transverse area of midship section, (equal to 297 feet) and the bulk of displacement. The engines are also light, weighing less than 100 tons, working steam at a moderate pressure, and consuming only three-fourths of a ton of coal per hour. The weight of vessel and cargo, at 11 feet draught of water, may be set down at 1,400 tons gross. Under such circumstances, an extraordinary speed cannot be expected.

The stern is shaped and built like that of a yawl boat, in order to permit the wheel to extend above the transom; the guards being carried around the stern as usual.

We have not yet been placed in possession of the particulars of her construction ; but in connection with the draught, and the remarks concerning her engines, and also those of the propellers "Buffalo" and "International," to be found in the following article, page 141, we give the calculations of hull, as we have worked them out from the draught.

The "Oriental" was built for freighting purposes only. Her upper deck extends the entire length of vessel, as usual in Lake propellers, upon which the cabins for the accommodation of officers and crew, only, are constructed.