New Iron Hardening Process.

Progress, Volume I, Issue 4, 1 February 1906, Page 82

New Iron Hardening Process.

Phosphorus, as is well known, has the property of imparting a certain degree of surface hardening to iron, but not without producing brittleness. The iron is made to assume a course structure, in which the crystals are comparatively loosely bound together. This effect of phosphorus of loosening the coherence of the molecules of the iron greatly facilitates the absorption of the carbon by the iron. The carbon rapidly penetrates the iron to a considerable depth, imparting great toughness to the core and nullifying the comparatively slight defect constituted by the inconsiderable brittleness of the surface. Two Prussian inventors apply this principle in their process for hardening iron by heating the same in a tempering powder, consisting of organic nitrogenous substances containing a high percentage of f usable ash, and employing phosphorus as the medium for the introducing of carbon into the iron, Without prejudicially affecting the welding properties of the iron, it imparts such a degree of hardness thereto that it can neither be cut nor chipped by the best steel used. In order to harden the surface of about 200 kilograms (441 pounds) of iron to a depth of 1 millimeter (.0394 inch) by means of this process, the pieces should be embedded in a added a mixture of 300 grains of yellow prussiate, 250 grains of cyanide of potassium, and 400 grains of phosphorus. The receptacle is well closed, luted with clay, etc., and raised to a clear red or white heat, whereupon the material treated is immersed in a glowing condition in a water or other bath.

It will be surprising if the primitive and slow street-sweeping machines now in general use are not supplanted by the steam sweeper devised by the Hartford Motor Manufacturing Co., of Connecticut, U.S.A. Each of these is equipped with a water-tube boiler and engine at the rear, and will traverse any surface at the rate of four miles an hour. No inconvenience is caused to passers-by, as not a particle of dust is scattered. In the centre of the machine is a rotary brush, upon which hot steam is constantly directed. As the dust is taken up it is damped by the steam, and so prevented from rising into the air. The broom throws the street sweepings into a large dirt-box, which can be quickly" emptied. With what is termed an eight-foot sweeper, 18,000 square yards of road . surface of any description can be dealt with in one hour, at a cost of four shillings. The machine is wheel steered, with rubber tyres on artillery wheels, and will pick up anything, from the finest dust to half bricks.

An instance of what the milking industry does for Taranaki is given by the " Daily News." During December nearly was distributed amongst the factory suppliers near Manaia. The five companies doing business around Eltham — Ngaire, Mangatoki, Lowgarth, and Kaponga — distributed over .£21,000.