MECHANICS AND USEFUL ARTS. 43 



train, so that there is no overstraining of any one pair of the wheels. 

 The buffer consists of a cylinder and piston working through a stuf- 

 fing-box, the piston-rod carrying at its terminus the buffer-head. The 

 cylinder is filled with water, and is connected by a small tube, with 

 another cylinder, containing air, which is above it. When the buffer 

 strikes any object, the water is forced up into the cylinder, and by the 

 elasticity of the air acted on by the water, the engine and train are 

 arrested without injury, and there is not the least shock on the re- 

 bound. A strong bulk-head of timber was fixed in the angle of the 

 wall which formed the terminus of the temporary railway, and the 

 passengers in the cars, after being wheeled along as if they were to 

 be dashed against the wall, received only a gentle shock. London 



a 

 Mining Journal. 



NEW COUPLING-CLAMPS. 



THE object of this invention is to supersede the present system of 

 attaching and detaching railway cars, and it is called the " double- 

 ratchet clamp." The utility of such an invention will be obvious to 

 every rail-road traveller, when he contrasts it with the present defect- 

 ive method. The links by which the cars are fastened together are 

 so constructed as to prevent any "play" between them, more than 

 that allowed by the buffer-springs, so that the jolting which now takes 

 place at any sudden stop is completely avoided, while the time neces- 

 sary for coupling and uncoupling is much less than at present, and it 

 is not necessary to go between the cars, thus avoiding all danger. 

 The cramp consists of two trucks, or hoops, connected by what is 

 termed a right and left-handed screw, the peculiarity of which is, that 

 bv turning it in one direction the links are drawn closer together, 

 and by turning it in the other they are extended. It is worked by an 

 ingeniously constructed toothed wheel, fixed to the middle of the 

 screw, about which a lever is provided with a click and spring for the 

 purpose of taking hold of the wheel, in which it is allowed to traverse. 

 All the room required for the action of the cramp is about 7 inches for 

 the traversing of the lever, and when being used it is hooked to the 

 side-chains of the car. and by its action the buffers are compressed and 

 the cars drawn closer together; the connecting link is removed or at- 

 tached with great ease and much saving of time. It is the invention 

 of two gentlemen connected with the Northwestern (England) Rail- 

 road, who have therefore had an opportunity of seeing the defects of 

 the present system. 







NEW SURVEYING INSTRUMENT. 



f 



A COMMITTEE of the Franklin Institute, to whom was referred for 

 examination the new surveying instrument of M. Villeroi, which is 

 intended to give the distances between the stations by means of a sin- 

 gle observation through the instrument, without the use of a chain, or 

 any other measuring apparatus, have reported that " it is a valuable 

 addition to our surveying apparatus." The instrument consists of an 



