This attachment, invented by Mr. Doutney, whose address is care of Messrs. Doutney Bros., 439 Broadway, New York city, closes the cock by means of a spring, and prevents it remaining partly open when the gas is turned off. It may be attached to any burner now in use. One end of a spiral spring, Fig. 2, is secured to the key and the other end to the casing surrounding the spring. The spring keeps the\lock closed. and when the key is turned to open the cock the spring swings it back again, thus closing the cock automatically. On the upper end ef the key is a disk formed with ratchet teeth engaged by a lever, Fig. 1, to one end of which a cord is secured. A spring keeps the lever engaged with the teeth. The key is locked in any position, whether the gas is to be turned on full or only partially, by the lever engaging with one of the teeth of the disk. To extinguish the gas it is only necessary to pull the cord, when the key is released and is turned by the spring, thereby closing the cock effectively and preventing any escape of gas. This attachment will prevent loss of life by careless or intoxicated persons leaving the gas key half way open, or by their turning off the gas and then turning the key partly open again. [t will also prevent fires caused by the key being left open, and will prove to be of great interest to fire insurance companies and hotel keepers. Bending Iron Cold. Undoubtedly that iron which is so tenacious or coherent in its particles as to be bent forward and back-ward.without showing visible disintegration is better tougher) than that which cracks or crinkles under similar treatment. But no iron can sustain its integrity under this treatment. This statement does not refer to iron bent while plastic with heat, but means iron at the ordinary atmospheric temperature. All manufactures and structures of wrought iron that assume such a quality in iron without permanent injury are faulty; iron cannot stand the strain of cold bending without injury, the injurious effect perhaps not being perceptible if the bending is slight and not often repeated, but nevertheless existing. The deduction from these premises is that wrought iron should be formed and fitted while plastically hot for the position it is to retain, just as cast iron is made to form. Still, wrought iron has a limit of safe elasticity—of resiliency—not allowable to even the best of cast iron; and in this quality of recouping, wrought iron is superior to cast iron. The idea sought to be conveyed is that wrought iron is not a mere metallic putty, that can be bent and rebent at will without losing its tensile character or impairing its tenacity. Some recent experiments prove that wrought iron tends to disarrangement of particles, to change in structure, to weakening in mass, by being bent when cold, even though the bending is a gradual curve and not an angular change of direction. A bar of square section was cut off in the lathe per-fectly square, and subjected to bending until it formed a segment of about one-third of a circle. It was noticed that the squared ends gradually changed from their perpendicularity to the length of the bar, the upper or rounding portion being shortened, so that measurements showed that the convex side of the curved bar had not so much elongated as the convex side had shortened. It was evident, therefore, that the bar had not moved in the bending as a whole, but rather as a series of superimposed plates might have been moved. Cutting the bent bar in two and examination under the microscope gave indications oi a stretching, and in some cases of a rupture, of the fibers. An attempt was made to verify this apparent demonstration, by the bending of a pile of thin strips of machine steel of a mass corresponding with the iron bar but it was found that the skin of each strip had a tenacity or resistance greater than the body of the strip, owing to its being compacted in passing through the rolls in its manufacture. Still, enough was shown to indicate that wrought iron (and steel—mild steel) was liable to a dangerous displacement of fiber by being bent while cold. Trunk-Lines ,in the United States. The tendency of the railways in the united States has been to combine into systems forming some of the longest lines of continuous railway administration in the world. The whole railway mileage in the Unitec States and Canada is about 120,000 miles, and nearly half, or 57,954 miles, is in the hands of 15 companies which in turn represent the amalgamation of a greate number of corporations. The magnificent distance traversed by these railroads are as follows: Miles. Missouri Pacific......................................... 6 045 Chicago, Milwaukee, and St. Paul.......................... 5,804 Chicago and Northwestern.................................. 545 Pennsylvania.............................................. 4,807 Union Pacific............................................. 448 Central Pacific................. .....................,..... 4,194 Canadian Pacific......................................... 348 Wabash, St. Louis. and Pacific...........................307 Vanderbilt roads..................................... 3,066 Grand Trunk ...........................................350 Atchison, Topeka, and Santa Fe..........................3,799 Southern Pacific......................................... 389 Baltimore and Ohio....................................... 237 Northern Pacific....................................... 249 Louisville and Nashville..................: ...............266 Total......................57,954 The Binns Gold and Silver Fabrics. The Binns Patent Band Co., manufacturers, Ran dolph Mills, Randolph St. and Columbia Ave., Phila. Pa., exhibitors at the New Orleans Exposition, havi been awarded three gold medals of the first class, a the highest award in group 5, class 507: One gold meda for gold and silver trimmings, one gold medal for bul lion cords, one gold medal for bullion yarns. The abov firm have been running day and night for severa months past. Leedham Binns, of the above firm, i the inventor and patentee of the machinery used b this firm.