MECHANICS AND USEFUL ARTS. 33 



With a company of twelve persons, the passage from Hoboken to Jersey 

 City was made in eighteen minutes, against wind and tide. The wheels 

 are 5 feet in diameter. 



A NOVELTY IN STEAM NAVIGATION. 



MESSES. STEVENS, of Philadelphia, have built a steamboat on a new 

 model, which may perhaps be best described by giving their specification 

 of claim in applying for a patent. 



" What we claim as our invention is applying air to the immersed 

 surface of a vessel in motion, as described, and thus we interpose, by a 

 continuous or intermittent supply, a stratum of air between the im- 

 mersed surface or portions thereof, of the vessel and the water, for 

 the purpose of reducing the friction of the water. We also claim the 

 recesses on the immersed surface of the vessel, formed by the scales 

 or other irregularities, or any thing substantially the same, when com- 

 bined with the supplying of air, for the purpose of distributing the 

 air, and for retaining it more perfectly and for a longer time between 

 the surface of the vessel and the water; but it is to be understood 

 that we do not claim those recesses independently of their connection 

 with the use of air to reduce friction. We also claim the plates over 

 the air apertures, to reduce the pressure required for the discharge of 

 the air, but this we claim only when air is used as a means of redu- 

 cing friction. We also claim the apertures made in the stern of a ves- 

 sel, communicating with the atmosphere by pipes or other conductors, 

 for the purpose of diminishing that resistance produced by the motion 

 of the vessel from the motion of the water, commonly called the suc- 

 tion of the stern ; we do not claim the use of these apertures except- 

 ing in connection with paddle-wheels, screws, or other propelling 

 agent." 



NEW ENGLISH IRON STEAM-FRIGATE. 



WE copy from a London journal an interesting account of a new 

 steam-frigate, recently constructed for the British navy. Her length 

 from the figure-head to the taffrail is 270 feet, while that of the keel 

 is 221 feet 4 inches; her greatest breadth is 41 feet, and the depth 

 29; the tonnage is 1,979 tons. She is called the Simoom, and is pro- 

 vided with a screw-propeller of 16 feet in diameter, which is driven 

 by two engines of 350 horse-power, which are placed below the sur- 

 face of the water, in order that they may be protected from shot in 

 time of action. The manner in which she is built, with reference to 

 strength, is somewhat peculiar. The keel and stem are of solid iron 

 bars, 9 inches deep by 5 thick, and the stem is of one piece of this 

 breadth and thickness, and upwards of 40 feet in length. The stern- 

 posts are of iron of the largest size, and the frames are of large-sized 

 angle-iron and are placed at short distances apm-t : the floor-pieces at 

 the bottom of the frames are 2 feet deep. On the top of the floors 

 there is a large box keelson, formed of iron, extending fore and aft the 

 ship. The outside plates or skin of the ship are one inch in thickness 



