from the pits at Kray, and then carefu photographed. The bars were 7 inche sectional area of 62 square inches. The weights of the three kinds of bars before an In the Schweizerisches Gewerbeblatt of 8 following tests of delta-metal were record locomotive engines of the Pilatus mountain was required which could be cast, and po time great tensile strength and elasticity. found to answer these requirements; the v brake gear for the engines were of this ma very satisfactorily. The castings were to Tetmayer of Zürich, the results showing of 21 to 23 tons per square inch, with 30 to 40 per cent on a length of 77 inches." also had the following tests made: One pinions having been in use for a long tim worn about of an inch, so that their thi was inch, and at the top inch, by a bre It was tested to show what power woul break such a tooth. The test, made by Pr gave the following result :— P. AL Р 32 5 9 10 12 14 15 0 0.015 0.019 0.059 0.098 0.133 0 19 20 21 21 AL 0.295 0.354 0.472 | broke. P indicating the stress in tons, and AL decimals of an inch of the distance L ori 23 inch. Both as regards P and AL unexpectedly favourable. The following test of delta-metal (forging) was made at Lloyds Proving House, Cardiff: The stalk of a valve spindle-inch diameter at small end, drawn out of a 2-inch chill cast delta - metal billet, was cut from the forging, and tested with results as per copy below: (The sample was reduced in centre for testing.) 1 WHITE BRASS § 44. Alloys of copper and zinc containing less 45 per cent of copper cease to have a yellow colour. alloys containing from 40 down to 30 per cent of co are silver-white, and with less than 30 per cent of co the colour passes from gray to bluish-gray, having a gre resemblance to metallic zinc as the proportion of that m is increased. The silver-white alloys break with a choidal fracture, and the more zinciferous alloys wi fracture more or less crystalline. In consequence of brittle nature of white alloys they cannot be used rolling and wire drawing, but some of them are used pressed work, when too strong a pressure is not requ Some of them are known by special names, thus: : § 45. Birmingham Platinum and Platinum Lead used for certain castings, but the composition is vari according to the taste of the manufacturer. The follo will illustrate this point : The above alloys are used for buttons by casting the moulds giving sharp impressions, the letter or crest subsequently brought out by careful pressing. Other for buttons consist of § 46. Sorel's Alloys.-These alloys are distinguish great hardness and considerable tenacity. They cas and can readily be detached from the mould. Th largely used for statuettes and other artistic work, v after suitable bronzing, are brought into commerce as bronze. The following mixtures are recommended : : Iron is used in the form of turnings, and copper and zinc under a layer of charcoal. readily volatilises it is advisable to emp containing iron, by which a more uniform with the minimum loss of zinc. § 47. Fontainemoreau's Bronzes. 1 bronzes are said to answer well for chill-ca being poured into iron moulds. By this m are rendered more homogeneous, because`tl prevents the separation of the constituent with their respective densities. The hi nature of the zinc is changed by the addition or lead. The following are the proportions § 48. These are copper-zinc alloys employ the various parts of articles together by fusion must, therefore, have a lower melting point t to be soldered, but the fusing point of the approach, as nearly as it conveniently can, t article, as a more perfect and more tenacious thus be effected. Brass solder belongs to the as hard solders, or brazing solders. It ma as a general rule that the melting point of alloys is higher in proportion to the amoun present, and therefore any quality of brass m into a suitable solder by adding zinc or copper |