The safety-tube, T, which is attached to the electrolyzer, permits of the escape of the hydrogen which is produced during the chemical reaction, and fixes, through an alkaline solution contained in the reservoir, B, the chloride whose escape might discommode the operator.
As may be conceived, the slow transfer of the saline solution from the receptacle, C, to the electrolyzer, and its rapid conversion into decolorizing chloride, as well as its prompt application upon the materials to be bleached, presents important advantages.
While, in the present state of the industries that make use of bleaching chlorides, the chloride of sodium is converted into hydrochloric acid, which, in order to disengage chlorine, must in its turn react upon binoxide of manganese, we shall be able, with this new method, to utilize the chloride of sodium, which is derived from ordinary salt works, and extract from it the constituent elements of the hypochlorite by a simple displacement of molecules produced under the influence of an electric current.
Another and very serious advantage of electric bleaching is that of having constantly at hand a fresh solution of hypochlorite possessing a uniform decolorizing power, which may be regulated by the always known intensity of the current.
We must remark that the hypochlorites require a certain length of time to permit the chlorine to become disengaged, and that, besides, all chlorides, bromides, and iodides that are isomorphous are capable of undergoing an analogous chemical transformation and of being employed for the same purpose. This is especially the case with the chlorides of potassium or barium, the bromides of strontium or calcium, and the iodides of aluminum or magnesium. On another hand, as sea water contains different chlorides, it results that it might serve directly as a raw material for bleaching textile fibers. Then, when the solution of chloride of sodium has been deprived of its chlorine by electrolysis, there remains a solution of caustic soda which may be utilized for scouring fibers.--H. Danzer, in Le Génie Civil.
IMPROVED SPRING TRACTION ENGINE.
Messrs. J. & H. McLaren, of the Midland Engine Works, Hunslet, Leeds, England, for several years past have devoted considerable attention to the question of mounting traction engines on springs. The outcome of this is the engine in question, the front end of which is carried by a pair of Timmis spiral springs, resting on the center pin of the front axle, which is on Messrs. McLaren's principle, which enables it to accommodate itself to the inequalities of the road without throwing any undue strain on the front carriage. The chief difficulty hitherto has been to mount the hind end on springs without interfering with the spur gearing, which must be kept perfectly rigid to prevent breakage of the cogs. This is entirely provided for by the new arrangement, whereby all the spring is allowed for in the spokes of the wheel itself, which will be clearly seen on reference to the illustrations, in which Fig. 1 is a perspective view of the engine, while Fig. 2 shows a detail view of the wheel. The rim of the wheel is built up in the ordinary way of strong T-iron rings, with steel crossplates riveted on. The nave of the wheel has wrought-iron ribs to which the spokes are bolted. These spokes are made of the best spring steel, specially manufactured and rolled for the purpose, 9 inches wide and ½ inch thick. They are bent in a pear shape, with the narrow ends fastened to the nave, and the crown resting upon the rim of the wheel, where they are divided, and held in their places by means of clip fastened with bolts. When the weight of the engine comes on these spokes, those nearest the ground are compressed and those, at the top are elongated a little. In order to avoid any of the driving strain passing through the springs, a strong arm is fixed on the differential wheel and attached to the rim as shown in Fig. 2, so that the springs have really no work to do beyond carrying the weight of the engine. Messrs. McLaren naturally felt a certain amount of diffidence in placing their invention before the public until they had thoroughly tested it in practical work. This, we are informed, they have done, with the most satisfactory results, during the last five or six months; and they have a set of springs which ran during that time between 2,000 and 3,000 miles, besides which there are several of these spring engines in daily use.--Iron.
