was 7° 7'; the projectiles used being, 1, the Whitworth steel-shot with a flat head; 2, a hemispherical-headed shot; 3, a shot with a head of the form advocated by Major Palliser. While in the first case the shot which struck close to the spot aimed at, in the second case it struck considerably, and in the third very much above that point. Mr. Whitworth, however, went rather out of his way, and certainly beyond the scope of his paper, to attack the material as well as the form of the chilled-iron shot. His objections to that projectile were: 1, that when fired at a considerable angle against an armour-plate its form causes it to glance off, while owing to the brittleness of the metal of which it is composed it breaks up; 2, that the consequent weakness of the metal necessitates a greater thickness of the sides and reduces its internal capacity as a shell.

In the discussion which followed, Mr. Bramwell defended the Palliser shell, and on the point of economy alone placed it far above a steel one. A steel shot he estimated to cost five times as much as one on the principle of Major Palliser. Its efficiency as a projectile he illustrated by the observation that a fragment of a steel shell after being fired against an armour-plate would be found to be quite hot, while in the case of one of chilled-iron no appreciable heat was developed.

In supporting Mr. Whitworth's claims for the superiority of a flat-headed shot in penetrating water, Mr. Hawksley argued, that on the principle of a flat stone selected by boys in playing "duck and drake," it seemed more probable that a projectile with a conical head would be deflected upwards from the surface of the water-in fact it would tend to ricochet. The smaller the angle between the direction of the shot and the surface of the water, the greater would be this tendency. It seemed to be also admitted by more than one speaker, that although a conical-headed shot might be superior to one with a flat head when striking at right angles, it was decidedly inferior when the angle was oblique.

Mr. Mallet called the attention of the meeting to some experiments conducted by the Russian General, Mayevski, which seem to show that the ogival-headed projectile is superior to the flat-headed, both for direct and oblique penetration. When a flat-headed shot strikes obliquely, it has a tendency to slew round and fly off backwards. On the contrary, while the ogival-headed shot also has a tendency to slew round, the result is to bury the point in the face of the armour, whereupon the shot proceeds to force its way into the plate almost the same as if it had been fired at right angles. A certain amount of power is lost even in the case of the ogive, but that which remains is exercised usefully.

Considering the national importance of the manufacture of iron and steel, the great improvements which have been lately introduced into it, and the necessity of still further reducing the con

sumption of coal, which, on good authority, threatens at no very distant period to outstrip our resources; it was not surprising that the papers on this subject read before the mechanical section were looked forward to and listened to with the greatest possible interest. The paper, by Mr. C. W. Siemens, "On Puddling Iron," was an attempt to trace the course of the chemical action which takes place during the puddling process; and the deduction drawn was, that the present method, which has now been maintained for many years without change or improvement, involves great loss of metal, waste of fuel and human labour, and an imperfect separation of the two noxious ingredients, sulphur and phosphorus. Experiments on a large scale, and a series of analyses of the iron in different stages of the process of puddling, appear to show that the molten metal is mixed intimately, in the first place, with a molten portion of the oxide or cinder (technically called the fettling) which forms the lining to the iron tray of the puddling chamber; that the silicon is first separated from the iron, that the carbon only leaves the iron during the "boil," and that the sulphur and phosphorus separate last of all while the iron is "coming to nature.' The object of Mr. Siemens was to show that much of the waste which takes place during this complicated action could be avoided by the use of a puddling hearth, heated by means of one of his regenerative furnaces, to the advantages of which he drew particular attention. These are, that the heat can be raised to an almost unlimited degree, that the flame can be made at will-oxidizing, neutral, or reducingwithout interfering with the temperature, that draughts of air and cutting flames are avoided, and that the gas-fuel is free from pyrites and other impurities which are carried into the puddling-chamber from an ordinary grate. A furnace erected, on this principle, which has been in operation at the Bolton Steel and Ironworks for eighteen months, has given most excellent results; and the process is about being adopted by Messrs. Kitson, of Leeds, and others in this country.

The production of steel by means of the mutual reaction of pigiron, and wrought or other decarbonized iron, has been often attempted, but in consequence of the insufficient means of ensuring a very high temperature, without any practical success. Lately, however, Messrs. Martin, of Paris, have succeeded by means of the Siemens' regenerative furnace in obviating this defect, and it was to their process under the name of the Siemens-Martin process, that Mr. Ferdinand Kohn drew attention in his paper "On the Recent Progress of Steel Manufacture."

To the Messrs. B. Samuelson and Co., of the Newport Works, Middlesborough-on-Tees, is due the credit of being the first in the United Kingdom to manufacture steel for commercial purposes by this method, and, as yet, these are the only works established

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solely for this purpose in the country. One of the great advantages of the process, and that which fits it more particularly for the Middlesborough district, is that by it a comparatively impure metal, as the Cleveland iron is known to be, can be converted into steel at a price inferior to that of the Bessemer steel, which requires tolerably pure hæmatite iron. The process, as described by Mr. Kohn, consists in adding to a bath of pig-iron, kept at a high temperature by means of the regenerative furnace, measured doses of wrought-iron, until the stage of complete decarbonization is arrived at; the operation is then completed by the addition of a certain percentage of pig-iron, or of the well-known alloys of iron and manganese. Generally, the Siemens-Martin process appears to have a wide range of applicability: it can work up the waste of other modes of steel manufacture, it can utilize old materials, especially wrought-iron and steel, and it is applicable to white pig-iron, or pig-iron poor in carbon.

Mr. J. Jones, Secretary to the North of England Iron Trade, read a paper "On some Points affecting the Economical Manufacture of Iron," in which he introduced to the notice of the meeting the Wilson Fire-Grate and the Newport Furnace, both of which, he submitted, effected a considerable saving of material and fuel in the puddling process. Without diagrams or a longer description than our space admits of, it would be difficult to convey any clear idea of the manner in which these inventions work. The principle of the Wilson-grate is the complete combustion of the fuel before it comes to the furnace chamber, and, as has been proved from results obtained by working for a considerable length of time, the quantity of fuel required per ton of puddled iron is from 20 to 25 per cent. less than in the ordinary furnace. In the Newport furnace attention has been paid to the utilization of heat, and the waste heat is again made available: in principle, it partakes somewhat of the regenerative character of Mr. Siemens' invention. By the use of this furnace it is stated that a saving of from 25 to 30 per cent. of fuel is effected. Mr. Jones also referred to the Radcliffe process of puddling, by which five or more balls are withdrawn simultaneously from the furnace, and treated together under a heavy steam-hammer with a quick action. He claims for this method the advantage of producing homogeneous iron, not liable to lamination, in a time considerably less than that required under the process ordinarily adopted.

A paper of the greatest possible public importance was read by Mr. L. E. Fletcher "On Coroners' Inquests and Boiler Explosions." Starting from the fact that since the commencement of 1855 up to the 31st July last, 464 boiler explosions, by which 789 persons were killed and 924 injured, had occurred in different parts of the

kingdom, he showed how necessary it was for the preservation of life that in every case the strictest possible investigation should take place as to the cause of the catastrophe. He urged more particularly the granting of power to the coroner to call in professional engineers to investigate and report on the condition of the boiler. Frequently the most frivolous and absurd reasons for the explosion are given and accepted by the jury, resulting in most cases in a verdict of "Accidental death," while the boiler, which in many instances, owing to defective construction, or wear and tear, is really the root of the evil, is left unexamined. In such cases, it would be possible, if the course pointed out were adopted, for the relatives of the dead or injured persons to recover pecuniary damages from the party really in fault; whether the manufacturer who has put bad material into the boiler, or the owner who has neglected to have it periodically inspected and reported sound. Especial reference was made to the Association for the Prevention of Steamboiler Explosions, by means of which every owner could assure himself, at a moderate cost, that his boiler is in a condition fit for working without endangering the lives of all in its neighbourhood. In the discussion which followed this paper, Mr. Fletcher's arguments were illustrated by reference to a boiler explosion which occurred in the city of Norwich about two years ago. The cause of this disaster was simply that the boiler was a bad one, though new, and made under a special contract as to the quality of the plates; and this was recognized by the jury in their verdict, resulting in the recovery of heavy damages from the maker to the amount of 2,0007.

Professor Rankine contributed a paper "On the Probable Connection between the Resistance of Ships and their Mean Depth of Immersion;" and Mr. Merrifield one "On the Necessity for further Experimental Knowledge respecting the Propulsion of Ships." Both of these papers referred to unknown elements in the resistance which vessels meet with in their passage through the water, though those elements may be due to different causes; and urged the adoption of experimental researches for the purpose of determining them.

Interesting papers were also read by Captain Douglas Galton "On a New Ventilating Fireplace;" by Mr. P. Le Neve Foster, jun., "On the Irrigation of Upper Lombardy by Canals, to be derived from the Lakes Lugano and Maggiore;" and by Mr. J. H. Gwynne, "On an Improved Centrifugal Pump."

INTERNATIONAL CONGRESS OF PRE-HISTORIC

ARCHEOLOGY.

THE third meeting of this Congress was held at Norwich, simultaneously with the Meetings of the British Association for the Advancement of Science. It was commenced on August 20th, by the President (Sir John Lubbock, Bart.) reading the opening address, which was chiefly remarkable for containing a brief reply to the articles in Good Words' by the Duke of Argyll, wherein His Grace endeavours to show that there is no proof whatever that such ages as the Paleolithic, Neolithic, Bronze, and Iron, ever existed in the world, chiefly, it would seem, because archæologists cannot show that they were universal, as the same age which was an age of stone in one part of the world was an age of metal in another. This fact is perfectly true, and has always been admitted by Pre-historic Archæologists. Sir John asks, Would the Duke of Argyll object to the use of the term "Christian Era," because we have Heathens existing now as well as Christians? This is an unfortunate reply, and its fallacy will certainly be exposed by so rigorous a logician as the Duke of Argyll. We denominate this the "Christian Era," because it succeeded the birth of Christ, not because it is characterized by the prevalence of Christianity. The remainder of the address was a good popular exposition of the leading facts and principles of Pre-historic Archæology.

On the 21st (Friday), after a paper by E. B. Tylor, Esq., “On Pre-historic Races and Modern Savages," a great part of the day was occupied with reading and discussing two papers "On Stone Circles," &c.: the first, on those of Scotland, being by J. Stuart, Esq.; and the second, on the Sarsden Stones, &c., of Berkshire, by A. L. Lewis, Esq. The former author inferred that stone circles were monuments of the dead, and the latter, that they were temples. The question of temples versus tombs produced an animated debate. Post-historic Archaeologists may some day quarrel over this question applied to our churches. They will find sepulchral remains in most of them, but not in all, and other evidence of the same nature as that we possess about Stonehenge, Carnac, &c. The probability to our mind is that such places were always temples and sometimes tombs. The other papers read this day were, " On Rock Sculptures," by H. M. Westropp, Esq.; and "On the Antiquities of the Pacific Islands" (which are not at all ancient), by J. W. Lamprey, Esq.

On Saturday, Mr. Busk exhibited an interesting collection of stone implements from South Africa, some of which had received a