A new steamboat, named the Charlotte Van-derbilt, has been built in this city, for the purpose of carrying out Captain Whittaker's method of propulsion, illustrated on page 188, Vol. XI., SCIENTIFIC AMERICAN. But although it should have been running on the North river long before this, it has not made its trial trip yet, and the inventor objects to her being allowed to run, on account of some new untried valve gear having been put on against his wishes. It is a handsome steamboat, and has a number of peculiarities. Its length is 210 feet, bow very sharp, with fine water lines; it has considerable breadth amidships to give stability in the water, as its draft is very light, being less than three feet at the bow. The interior of the hull, under the lower deck, is divided into sixteen wrought iron water-tight compartments or cells. It was built for great speed to run between New York and Albany as a day boat, to make as good time as the railroad ; and it is, in f ac t, a locomotive steamer in regard to her engines. She has a screw propeller at each side, in place of paddle wheels, and each propeller shaft is driven direct by two locomotive oscillating cylinders. The screws are fourteen feet in diameter, and have twenty-five feet pitch. The cylinders are two feet bore and two feet stroke, and it was designed that their valves should be worked by eccentrics from the propeller shaft, with the old and well tried link motion. Instead of this, the valves are arranged to be operated by a bell crank arrangement attached to the piston rod, an untried method. We should really like to see this method of propulsion fairly tested in our waters, as it is said to be very successful on Lake Erie, and if so, its economy in room for machinery and first cost is very great. The engines and boilers only weigh forty-five tuns, and occupy a very small space. They are intended to do as much work as common steamboat engines and boilers of two and three hundred tuns weight. It was calculated that the screws would make one hundred and twenty-five revolutions per minute, with the steam in the boilers at 100 lbs. pressure. At this rate, the Charlotte Vanderbilt would attain to a speed of about thirty miles per hour, allowing fifteen per cent for slip. Thus, 125 X 25 -f- 88 = 35.51 —5.32 = 30.19 miles per hour, a most extraordinary speed for a steamboat.