118 ANNUAL OF SCIENTIFIC DISCOVEKY. 



forward. In this way stone may be cut in relief in an exquisitely fine man- 

 ner, and work which has heretofore required hours and days to accomplish, 

 may now be executed in a few minutes. 



EUGGLES'S EOTAEY SHEAES FOE SHEET METAL. 



A new tool, known by the above designation, has been lately introduced 

 for cutting sheet metal, and which is made in sizes adapted to the thin tinned 

 sheets or to the half inch boiler plate. One straight and one circular 

 cutter are employed, the latter being revolved and slowly moved forward by 

 the aid of a belt acting on a pulley at one extremity of the machine. The 

 knives or cutters of this machine are so set that then 1 edges do not come com- 

 pletely into contact, but only sufficiently near to ensure the separation of the 

 sheet. It is found in practice with the ordinary lever shears that the cut 

 invariably precedes the point of absolute contact of the knives, while it falls 

 behind the point where the latter begin to press upon the metal. All shears 

 compel the particles to slide past each other in the act of separation, and it is 

 found that the cohesion of the metal is destroyed as soon as it fairly com- 

 mences thus to slide, so that an absolute contact of the cutting edges in 

 Ruggles's shears would be worse than useless. In practice the edges are set 

 at a distance equal to half the thickness of the metal to be cut, and the sheets 

 are divided with a degree of accuracy and of smoothness unsurpassed by any 

 system yet devised. 



IMPLEMENT FOE CUTTING WIEE. 



An improved tool for cutting wire has been invented by "Wm. Grover of 

 Holyoke, Mass., Jr. It differs from the common knife-edged nippers only in 

 the shape of its jaws. They are made round ; in other words they are complete 

 disks of steel, with holes of different sizes through their surfaces, for the 

 reception of the wire to be cut. In its operation the handles are opened 

 until a certain sized aperture in one of the disks comes in line with its equiv- 

 alent opening in the other disk ; the wire is then passed through and clipped 

 by compressing the handles. The ordinary nippers are apt to bend the wire 

 in cutting ; they also leave a rough burr on the ends of the pieces. But with 

 Mr. Grover's improvement, wire may be very rapidly cut to any size or 

 length, without the least bending, and with perfect smoothness. Scientific 

 American. 



IMPEOVED SKATES. 



Two patents for improvements in skates have been patented during the 

 past year, by N. C. Sanford, of Meriden, Conn. The object of these inventions 

 is to give the skate elasticity so as to enable a person to skate with more 

 ease. Small tubes are placed vertically within the stock of each skate. In 

 these tubes are placed india-rubber springs connected with knees secured to 

 the runner, which is also thereby firmly attached to the stock, by which it 

 gives some spring to the foot, and its use is thereby rendered more easy. 



