G6 ANNUAL OF SCIENTIFIC DISCOVERY. 



the following manner : The inventor takes a strip, say frbni ten to thirty 

 feet long, and winds it into a circular cast-iron case, of about the same 

 depth as the width of the steel. In the side of the case is a grate or aper- 

 ture, through which a small portion of the outer coil of the steel is made 

 to protude. He then puts a cast metal lid on the top of the case, so as to 

 cover the whole of the steel, and places the case in a furnace, and allows 

 it to get red-hot, when it is removed by one workman, while another 

 seizes hold of the protruding end of the steel, and draws it through a pair 

 of cold steel, metal, or stone dies or plates, by which the steel will be hard- 

 ened, coming out fiat. The dies or plates are to be kept cold, by having 

 cold water applied to them, or they may be made hollow, and a stream of 

 water be caused to flow through them. Shorter and stronger lengths, such 

 as steel saw-blades, &c., are hardened, by placing them in a furnace, and 

 allowing them to get red-hot, and then quickly introducing them and sub- 

 jecting them to pressure between two dies or plates, mounted in a frame, 

 so as to form a press, by which means they are both hardened and pre- 

 vented from warping or buckling care being again taken to keep the 

 dies or plates, whether of metal or stone, cold by the application of water. 

 He tempers these articles in the ordinary manner, and the tapes or strips 

 as follows : After the strip or length of steel has passed through the dies 

 or plates, it is removed to a stretching- table, where one end is made fast 

 between screw-clamps, or otherwise, while the other end is clipped be- 

 tween another pair of screw-clamps attached to a leather strap, which is 

 fastened to a drum or roller turning in bearings, and furnished with a lever 

 or arm, which is weighed so as to produce a gentle strain on the steel. 

 The steel is then oiled or greased, and heat is applied to it from a portable 

 furnace or gas-light, attached to a flexible tube, or from any other source, 

 so as to blaze off the oil or grease, whereby a fine spring temper will be 

 imparted to the article operated on, and it will be left flat and straight. 

 Or a fixed gas-furnace is employed, and the steel drawn from the harden- 

 ing dies or plates, direct through the gas-furnace, thus becoming hardened 

 and tempered at one continuous operation. 



For the purpose of grinding both sides of a flat article, or the entire 

 periphery of a circular or similarly-shaped article, the inventor fixes upon 

 a central tube or axis, a grindstone in the form of a roller or cylinder, and 

 makes this stone plain or indented, with semi- circular or other grooves, 

 according to the shape of the article to be ground ; and over this grind- 

 stone roller he mounts another similar to it. Upon rotary motion being- 

 imparted to the rollers, and the end of the article to be ground being in- 

 serted between them, they will draw it through, but without grinding it ; 

 the article is then to be drawn or pushed by the workman, in a contrary 

 direction to the rotation of the rollers, and the grinding will then take 

 place in its passage between them. The sides of one of the rollers, when 

 the articles to be ground are flat, are also provided with collars formed of 

 grindstone, and of a larger diameter than that of the rollers, whereby the 

 edges, as well as the sides of the metal article, may be groiind, when re- 

 quisite, at the same operation. Means are provided for adjusting these 



