MECHANICS AND USEFUL ARTS. 29 



is fastened to the brace passes through the prop to the inside of the 

 carriage-top, where it connects with a hand-hold lever. By simply 

 moving this lever backwards or forwards, the top is let down or raised 

 up. Another handle, attached to a rod at the lower end of the brace, 

 may be used in the same manner instead of the hand-hold lever. To 

 use this single brace with double joints, the slats or bows forming 

 the frame-work of the top must be hung on the same centre. The 

 braces on the two sides of the carriage-top are connected together by 

 a rod, which lies against the back of the seat under the lining. By 

 means of this connecting-rod, the braces on both sides are operated 

 simultaneously by moving the lever. A spiral spring is wound around 

 the connecting-rod, one end being fastened to the back of the seat, and 

 the other to the rod itself. The spring is proportioned to the weight 

 of the carriage-top, two being sometimes used. As the top falls, the 

 spring winds around, so that it drops slo\vly and steadily, while a very 

 slight pull of the lever is sufficient to raise it. By means of a looped 

 cord passed over a nob, the carriage-top may be held at any angle of 

 elevation. Scientific American, Dec. 7. 



NEW STIRRUP-IRON. 



AMONG the gold medals awarded by the American Institute in New 

 York the present year, was one to Mr. Nathan Post, of East Cleveland, 

 Ohio, for a new stirrup. Its excellence consists in a spring-guard, 

 which allows the foot to go into the opening only a certain distance. 

 This guard, by means of a centre tube and screw, may be elevated 

 and lowered to allow the foot to go in a greater or less distance. 

 There are various other contrivances, and its whole effect is, that, if 

 the rider is thrown from his horse, it is impossible for his foot to stick 

 in the stirrup, for the guard throws it out at once. Scientific Ameri- 

 can, Nov. 16. 



HYDRO-PNEUMATIC LIFT. 



THE Glasgow Practical Mechanics' 1 Journal for March contains a 

 description of " Simpson's Hydro-Pneumatic Lift for Furnaces and 

 Railway Elevators." The principle is that known as flotation. An 

 air-tight sheet metal case, of sufficient displacement for the greatest 

 weight it is designed to raise, is immersed in a well containing water, 

 and attached, by means of a large vertical pipe of the same material, 

 to an upper platform rising between guides. When the case is re- 

 leased it will of course ascend, carrying upon its platform the articles 

 to be raised. The valve-apparatus for governing the motions, &c., 

 constitutes the novelty of the machine. The ''float-case" is made 

 spheroidal, and is connected, as has been described, to the platform by 

 a hollow pipe, closed above by the platform, and below perforated, so 

 that in the movement of the machine its bulk shall not materially af- 

 fect, by a greater or less degree of immersion, the usual level of water 

 in the well. The float-case itself is provided with a small pipe rising 

 in the centre of the large one, which opens to the air above by means 



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