MECHANICS AND USEFUL ARTS. 49 



CAPT. C. F. BROWN, of Warren, Rhode Island, has invented a 

 new and ingenious improvement in steering apparatus for vessels. The 

 head of the rudder-post is made of metal, with a helical groove run- 

 ning down on each side of it, and over this is placed a tube, with two 

 feathers on its inside, fitting into the grooves. Over the top of this is 

 another outside tube or cap, bolted by a flange to the deck, and on its 

 top is the wheel, having for its axis a screw, which works into a 

 thread opening in the second tube, and as the wheel is turned this 

 second tube is raised or lowered, and its feathers, thereby working in 

 the helical grooves of the head of the rudder-post, turn it round, and 

 from one side to the other, thus operating the rudder and steering the 

 vessel. The steering-wheel is horizontal, and there is an indicating 

 pointer on the post-head, which, as it turns, points to an index, and 

 enables the steersman to see every degree through which the rudder 

 moves. Scientific American, May 25. 



NEVv r LIFE-BOAT. 



THE London Times describes a new life-boat, the invention of Mr. 

 W. Bonney. Its peculiarity consists in the mode adopted for giving 

 it buoyancy. " This quality is communicated to the ordinary class of 

 life-boats by the fitting of hollow tubes round the gunwales or there- 

 abouts, and beneath the thowls. Mr. Bonney, while he does not give 

 up this method, adds another and a more scientifically working plan 

 to the old mode. On each side of the boat, from stem to stern, runs a 

 triangularly shaped chamber, formed by dropping a perpendicular 

 sheet of iron from the deck until it joins the bulge of the boat. Of 

 this triangle the deck is of course the base, the outer shell of the ves- 

 sel constituting one side, and the inner partition the other. The re- 

 sult is, that when the vessel is on an even keel, she floats just like 

 any other craft ; but, when she careens over, by the force of the wind 

 or any other influence, the buoyancy of the lee chamber comes into 

 play, and as the quantity of air forcibly submerged becomes larger the 

 greater the heel, it follows that the stronger the careening impulse 

 the greater is the resistance. From what we saw yesterday, and the 

 explanations we heard given, it is evident that no vessel built upon 

 this principle can, except under some very extraordinary circum- 

 stances, capsize. The quantity of air buried in the water, when 

 heeling over, would prevent it, and would cause her, even after sail- 

 ing on her side, to right herself as soon as the least decrease took 

 place in the careening power. Ordinary boats may fill with water 

 either by being dipped gunwale under by sheer force of wind or by 

 shipping a sea. In neither case would the catastrophe be of material 

 consequence to Mr. Bonney's gutta-percha cutter ; and for this simple 

 reason, that only a given proportion of her, that is to say, the space 

 left between the inside walls, can fill ; and that when this takes 

 place the air-chambers, now brought into play on both sides, are quits 

 sufficient, not only to keep her afloat and manageable, but to support 

 her reasonably well loaded with people. We saw her yesterday filled 

 with water, and \vith several hundred weight of ballast, besides that 



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