434 THE COLLIER,Y GUARDIAN March 1, 1918. This steel is made in two qualities: the “ A. W. Premier,” and the “ A. W. high-speed.” These are tungsten steels, the first containing 18 per cent, tungsten, and the second 14 per cent, tungsten. Another quality of steel has just recently been intro- duced, termed “ C. V. Brand,” a chrome vanadium steel, the special feature of which is its ability to withstand “ shocks.” It is used in all tools where a “percussive” action is maintained. In the manufacture of this steel only the very best brands of Swedish iron, free from impurities such as phosphorus and sulphur, are used. The percentages of iron and alloys are carefully weighed, and put into a crucible or “ clay-pot,” through an iron funnel, the crucible itself being placed in the melting or pot hole, which is heated by means of gas from a regenerative furnace. The operation of melting is a most impor- tant one, for should the contents of the crucible be improperly melted, the iron and alloys do not mix thoroughly together; whilst, on the other hand, if the melting period be carried on too long, the result would be equally as bad, as the steel would be brittle, with tendencies to cracking. At Openshaw, producer gas is used from which the Fig. 4. ... <0 A' O Ln L, \ i . z...W '■ 71 x '■ £ / - ■ ’ ■V-' / Fig. 5. Figs. 4 and 5.—Whitworth’ Interchangeable Guide Screw-Stock. by-products have been recovered. From the crucibles the molten steel is poured into ingot moulds, and after being re-heated are hammered under tilting hammers, or rolled to the section and size of bar required. The re-heating is carried out to temperatures depending upon the chemical composition of the particular ingots under treatment. In dealing with carbon steels, this question of tem- perature is a very important one. When making tools, such as taps, dies, chasers, or other tools that have to be machined, it is necessary to have the steel very care- fully annealed, which is usually done in “ muffles.” In addition to softening the steel, and rendering it easy to cut, annealing has the effect of bringing it into a more uniform and homogeneous condition by eliminating any internal stresses which may have been set up in the operation of hammering or rolling. After the tool is machined, it is hardened by heating to the required temperature in a muffle furnace, and cooled in an oil bath. In addition to screwing apparatus and gauges, the firm make every description of milling cutters, reamers, gear-cutting hobs, twist drills, broaches, and metal-cutting saws. For’ cutting metal in the operations of turning, planing, etc., the “ A. W. Premier ” quality is used, and for this purpose is unequalled in economy and efficiency; The difference between ordinary carbon tool steel and tungsten high-speed steel is that, with the former, when the temperature due to the friction of cutting reaches about 500 degs. Fahr., the cutter begins to lose its hardness, and its cutting capacity is in consequence immediately impaired; whereas with a tungsten steel the temperature of friction may extend up to 1,200 degs. Fahr, without the tools sensibly losing their hardness or cutting capacity. In fact, if the nose of a high-speed steel tool be closely observed during the operation of making a heavy cut, it will be seen that the point of the tool has become red hot, and will remain so for a long period without breaking down. Tungsten has the property of imparting to steel an intense hardness, at high working tempera- tures, at which carbon steels would fail. The use of high-speed steel has also proved to be economical in mechanical efficiency, inasmuch as a given horse-power will remove a greater quantity of metal at a high speed than a low one, the horse-power absorbed for each pound of metal cut being less. Foi- instance, it was found when cutting on hard steel with a s/1Gin. depth of cut and ’/jjin. feed, at a speed of 17 ft. per minute, 5-16 horse-power was absorbed; but on increasing the speed to 42 ft. per minute, the depth of cut and feed being the same, there was a saving in power of 19 per cent, on the work in hand. In another' experiment, increasing the depth of cut from 3/lrin. to fin., with the same traverse (l/lcin.), resulted in a saving in power of 28 per cent. One of the greatest advantages resulting from the use of this steel is that, when once ground, it will last for a very long time without requiring re-setting and grinding. With ordinary carbon steel this was a con- stant source of annoyance and loss. The steel is not difficult to work in the smithy, as might be supposed, but, of course, care must be exer- cised in regard to temperatures. It must not be made too hot, or continue to be forged when the heat has dropped below a good red. In the hardening process, the cutting edge should be first gradually heated up to a good red heat, and then quickly to a nearly white or brilliant yellow heat, and rapidly cooled in an air blast or oil bath. In conclusion, Messrs. Sir W. G. Armstrong, Whit- worth and Company Limited offer to their clients the benefit of their long and valuable experience in the use of standard tools made by them, and in the use of their special high-speed tool steel. The new special chrome-vanadium 1 ‘ shock ’ ’ steel will probably prove of immense value in the manufacture of percussive rock drills, since it has been abundantly proved that good tool steel, though expensive in first cost, is cheap in the end. The Rotherham Borough Council has decided to obtain a. report from Sir John Snell and Mr. Charles Merz as to the best method of affording a supply of electrical energy to Sheffield and Rotherham and the districts surrounding, Coal in Algeria.—A report states that coal has been discovered at Bel Hadir, about 22 miles from Colomb- Bechar, South Orannais. An examination disclosed an inclined bed of a thickness of 50 cm., which crops the surface of the soil over a length of 5 kiloms., and the breadth of which is at least 10 m. The coal, which, on analysis, shows 65 per cent, carbon, is now in use on the Algerian railways. Subsidence from Mining Operations.—At the Chancery Court in Manchester on Tuesday, the Vice-Chancellor gave his judgment in the action brought by the Westhoughton Urban District Council against the Wigan Coal and Iron Company Limited. He said the Council were the lessees of land at Westhoughton used for the purposes of a sewage works. They and their predecessors had been in possession of the surface under various leases since February 1875. and at the present time were holding under a lease dated August 25, 1914, from the Earl of Ellesmere. The lease contained a proviso that no liability should be incurred by the earl in respect of damage to the surface and buildings by the winning and working of the minerals. In February 1874 the defendants obtained a lease of the seams of coal subjacent to the land leased to the Council. Two seams— the Arley and the Yard—had been worked by the longwall system, and it was not disputed that the result of their operations had been to cause subsidence and consequent injury to the buildings. If the workings continued, the damage would increase. The defendants contended that they were entitled to the benefit of the proviso in the Council’s lease, and could let down the surface without 'paying compensation. On that point he decided against the defendants, and directed an enquiry as to the damages caused to the plaintiffs by the mining operations. The claim for an injunction failed. TAXATION, RATING AND VALUATION OF MINES.* By David Bowen, F.G.S., M.I.M.E. It is almost impossible to appreciate accurately the effects of a system of taxation, such as that introduced by the Finance (1909-10) Act, 1910, without analysing statistical and other records over a number of years both previous and subsequent to the imposition of the particular tax or taxes concerned. In the present case, the author’s difficulty has been enormously increased by two facts—the one responsible for the other—the present European war and the author’s military service both at the front and at home since early in August 1914. These two facts have made the work of reference exceedingly difficult, and the present paper was only rendered possible by post- poning the discussion of some vital considerations to a later date, the present paper serving as a general introduction to the whole subject. It is hoped that this arrangement will serve to render the second paper more complete, as members, by their remarks upon the subject-matter contained in this preliminary paper, may suggest important points affecting the general question which could then be fully discussed in the later paper. It is probable that for some years the State may have to resort to heavy and varied forms of taxation in consequence of the present war, and this institution may, perhaps, be of some assist- ance in determining what form of taxation and what amount may fairly be applied to mines, as distin- guished from other industrial concerns, without pre- judice to theii' proper development. Very heavy sums have been sunk by way of capital expenditure; labour troubles are constantly arising; engineering difficulties, particularly in connection with concealed coal fields, are becoming increasingly greater; and the ingenuity and resourcefulness of those directing mining concerns are being taxed to the uttermost. For the sake of completeness the authoi- has included in this paper a general outline of existing conditions, with a brief historical account, showing in bare out- line the development of both theoretical principles and the practical aspect of taxation. Principles cf Taxation and Taxing Systems. Bastable defines a tax as a “compulsory contribu- tion of the wealth of a person or body of persons for the service of the public powers.” In order to fulfil its functions, the State must be possessed of revenue, and although in early times the various forms of taxation were adopted on almost entirely practical grounds, since the close of the eighteenth century economists have sought to define the general principles which should govern taxation, and nowadays every proposal with a view to reforms in taxation is subjected to detailed criticisms not only from practical but also from theoretical grounds. As these general principles — widely accepted by both economic theorists and practical experts—form the basis of modern systems of taxation, it is con- sidered that a brief summary of them may be given here. Adam Smith expressed the general principles which, in his opinion, should govern taxation in the form of maxims, as follow : — (1) The subjects of every State ought to contribute towards the support of the Government, as nearly as possible in proportion to their respective abilities; that is, in proportion to the revenue which they respectively enjoy under the protection of the State. (2) The tax, which each individual is bound to pay, ought to be certain, and not arbitrary. The form of pay- ment, the manner of payment, the quantity to be paid, ought all to be clear and plain to the contributor and to every other person. (3) Every tax ought to be levied at the time, or in the manner in which it is most likely to be convenient for the contributor to pay it. (4) Every tax ought to be so contrived as both to take out and keep out of the pockets of the people as little as possible over and above what it brings into the public treasury of the State. In these four maxims there are embodied the prin- ciples of equality, certainty, convenience, and economy. Although these were for a time adopted by most economic writers, they have of late years been subjected to a good deal of adverse criticism. Bastable, for instance, suggests that taxation should be: (a) productive; (ft) economical—inexpensive of collection, and should retard as little as possible the development of wealth; (c) justly apportioned; and (d) elastic. That it should be (e) certain, and (/) convenient, he regarded as matters of less interest. Should any one canon conflict with another, the solution should be sought in the surrender of the less important one. Thus, the successful administration of the State being the final object, convenience, or even equity, may have to yield to productiveness. This introduces the rule of expediency, which, as Plehn observes, “ works in the most astonishing ways to prevent the execution of approved principles.” In the case of Coltness Iron Company v. Black (1881), Lord Blackburn stated his opinion as follows: — No tax can be imposed on the subject without words in an Act of Parliament clearly showing an intention to lay a burden on him. But when that intention is sufficiently shown, it is, I think, vain to speculate on what would be the fairest and most equitable mode of levying that tax. The object of those framing a Taxing Act is to grant to her Majesty a revenue; no doubt they would prefer, if it were possible, to raise that revenue equally from all, and, as that cannot be done, to raise it from those on whom the tax falls with as little trouble and annoyance and as equally as can be contrived ; and when any enactments for the purpose can bear two interpretations, it is reasonable to put that construction on them which will produce these effects. But the object is to grant a revenue at all events, even though a possible nearer approximation to equality may be sacrificed in order more easily and certainly to raise that revenue, and I think the only safe rule is to * From a paper read before the Surveyors’ Institution on Monday, February 25.