letters the author adopts pictorial symbols by which to represent the elements, and arranges them in a geometrical pattern to construct the compounds formed by their union. In the discussion which followed the reading of this paper, Drs. Atkinson, Russell, Stevenson, and Odling spoke briefly, and, in a general sense, adversely, as to the desirability of introducing the system to the notice of the student. Dr. J. H. Gladstone followed with a paper "On the Tetraphosphoric Amides," compounds produced by the action of water on the amidated oxychlorides of phosphorus; and the proceedings concluded with a paper by Mr. Carter Bell "On the Solubility and Crystallization of Plumbic Chloride in Water, and in Water containing various proportions of Hydrochloric Acid." The author finds the degree of solubility in pure water to be about 1 part in 121 parts, instead of in 135. The solubility in hydrochloric acid decreases up to a certain point, when the curve com mences to ascend. The meeting on May 7th was very fully attended, and many distinguished visitors were present to hear Mr. C. W. Siemens, F.R.S., deliver a lecture "On the Regenerative Gas Furnace as applied to the production of Cast Steel." The following is a very condensed account of this important lecture; and it is to be regretted that the many demands upon our space will not permit of its being given more fully. The lecturer commenced by briefly sketching the properties and modes of preparation of cast steel, which he defined as a compound of iron and carbon possessing the remarkable property of becoming exceedingly hard when heated and suddenly cooled. Steel containing 14 per cent of carbon partakes of the character of white cast iron, and below 0.3 per cent. the metal is incapable of being hardened. The presence of manganese improves the quality of steel, apart from its function in removing sulphur and other impurities. Tungsten, in quantities of about two per cent., has the remarkable property of increasing the power which steel possesses of retaining magnetism when hardened. This property of tungsten was illustrated in the lecture-room by a small permanent magnet of horse-shoe form, which supported twenty times its own weight from the armature; the celebrated Haarlem magnet being incapable of lifting a weight more than thirteen times heavier than itself. principle of Mr. Siemens's plan of heating is already well known. The fuel is heated upon an inclined fire-grate, where it undergoes a kind of slow combustion which results in the formation of carbonic oxide; this inflammable gas is then conducted from the "producer" to the hearth or working platform of the furnace, where it meets a current of air already raised to a high temperature, which enables it to burn with great intensity; and the excess of thermal power, instead of being allowed to pass direct into the chimney and thus become wasted, is forced to traverse an intricate structure of brick2 E VOL. V. The work, which absorbs so much heat that the escaping gaseous products of combustion rarely indicate a temperature above 300° F. At a suitable stage of the operation the gas-valves are reversed, and both carbonic oxide gas and air are forced to traverse these heated brick chambers in a contrary direction, so that they may in turn become the recipients of that heat which in ordinary constructions of furnaces would have been lost. The ashes and clinkers are in this way entirely separated from the region of manipulation, and are removed from the grate at intervals of one or two days. The author estimates the temperature produced by the combustion of the gas and air to be 1,000 to 1,300° F. when they are cold to begin with; but when they have been separately passed through the regenerator and thereby raised to a temperature of, say, 1,000° F. beforehand, the temperature of their combustion will be, say, 2,000°. The surplus heat from this will then raise the temperature of the regenerator still higher, and the gas and air will consequently attain a higher degree of heat before they unite. The platform of heat, so to speak, on which they commence their combustion, will be raised each time, until practically there is no limit to the degree of temperature which may be attained in this manner-the whole mass of the furnace, with its contents, having occasionally been melted down into one mass. The special furnace which Mr. Siemens has erected at Birmingham for the direct production of steel from the ore, has a tunnel-head or cylindrical hopper, fed with iron ore and small coke, passing through and raised above the crown of the regenerative gas furnace; the lower part of this upright cylinder rests in a bath of molten pig-iron, which dissolves the reduced (spongy) iron as quickly as it is separated from the ore. A blast-pipe descends through the stack of ore, and the process is interrupted when the steel is ready for casting, after which the charge of pig must be renewed. It is a very important point in connection with these furnaces, that the atmosphere of them may be changed at will into an oxidizing, reducing, or perfectly neutral condition, merely by altering the proportions of air and gas. After the delivery of this lecture, which was amply illustrated with experiments, specimens, and a series of diagrams and dissected models, an animated discussion followed, in which the President, Mr. Cowper, Professor Abel, Dr. Miller, Dr. B. H. Paul, Dr. Williamson, and Dr. Odling took part. On May 21st, Dr. Russell opened the proceedings by showing some experiments "On the Application of the Measurement of Gases to Quantitative Analysis." The author considers the system of measuring to be more accurate than weighing in a variety of analytical operations wherein gases are evolved, and the results which he has obtained certainly corroborate this view. In the discussion which followed, Dr. Williamson said that as a rule the process of measuring was more accurate than weighing; for, whilst we could not weigh closer than one-tenth of a milligramme, it was possible to measure volumes of gas within one-hundredth part of a cubic centimetre. Mr. W. H. Perkin then read a paper "On the Combining Powers of Carbon." This was very long and theoretical, and related to the inquiry whether all four affinities or combining units of carbon are of equal value. The proceedings were brought to a conclusion by a short paper by Mr. Parnell "On the Reducing Action of Peroxide of Hydrogen and Carbolic Acid." 6. ENGINEERING-CIVIL AND MECHANICAL. THE gradual, though, it is to be hoped, certain return of confidence in various existing undertakings, recently shown by the state of the money market and the quotations of shares, cannot fail to have exercised a beneficial influence on the progress of engineering schemes; but it must be acknowledged that there is still room for much improvement. Ship-building.-The state of trade in the northern parts has of late exhibited a decided improvement, but the same cannot altogether be said of ship-building on the Thames. Messrs. Napier and Sons of Glasgow have recently completed an armour-clad twin-screw turret-ram for the Dutch, and Messrs. Laird of Birkenhead, have launched two sister monitors for the same Government. The lastnamed firm are also building a turret-ship of 4,200 tons, and a broadside-ship of the 'Invincible' class for Her Majesty's Government, as well as a composite gunboat for service in the China seas. A gunboat on a new model has recently been built for the Admiralty, on the Tyne, from the designs of Mr. G. Rendel, of the firm of Sir W. Armstrong and Co.; this vessel is only 70 feet long by 25 feet beam, having twin screws driven by two pairs of condensing engines. She carries as heavy a rifled gun as any in the Navy, mounted in the fore part of the vessel in a line with the keel, and firing through a bulwark, or screen, over the bow, which is cut down and plated something like that of a monitor. On the Thames the Repulse, to carry eight guns, and of 800 horse-power, was launched at Woolwich Dockyard on the 25th April; and at Chatham, in addition to the Sultan,' a powerful new iron-clad ship, of the Herculus' class, has recently been laid down. There is now, it appears, no doubt about the closing of the minor Government ship-building yards, an order having been received for Deptford to shut up in the course of the year, and it is thought that Woolwich will, in all probability, follow Deptford. 6 On 25th April last, the first gunboat ever built in Ireland was launched from the yard of Messrs. Harland and Wolff of Belfast, which is one of six gunboats being built for the British Government. Docks and Harbours.-One of the greatest and most important recent additions to private dock accommodation on the Thames was made on 14th March, by the opening of the Millwall Dock basins and warehouses; and on 21st April the foundation stone was laid of the first of four large new Graving Docks to be constructed at Chatham. A new harbour under construction at Torquay, at the cost of Sir L. Palk, M.P., is rapidly progressing; it is intended to extend the harbour some 600 feet, and vessels drawing a much greater depth of water than heretofore will be enabled to enter it. A considerable sum is also about to be expended on the improvement of Great Yarmouth Harbour. Works for the improvement of the basin at Brest were commenced so far back as 1863, but after sixteen months of persevering efforts, the contractor failed to make a water-tight dam. Recourse was then had to the compressed air process, and a caisson was sunk, having a capacity of 2,427 cubic metres, in which forty men have been working day and night in four-hour shifts. During the recent visit of the Duke of Edinburgh to Australia, his Royal Highness laid the foundation stone of a fine Graving Dock at Williamstown, Victoria. River Improvements.-The works undertaken for the improvement of the Sulina mouth of the Danube appear to have been successful, the depth of the channel having been increased to an average of 15 to 16 feet, while the Sulina Pass, formerly regarded as one of the dangers which shipping had to encounter, has now become one of the best refuges on the coast of the Black Sea. Water Supply.-The Carnarvon Waterworks were opened by His Royal Highness the Prince of Wales on 25th April last. They are supplied with water from Llyn Quellyn, a lake situated about six miles from Carnarvon, and 600 feet above the level of the town. The new waterworks at Helensburgh were opened on 26th March last. The water is collected from two streams intersecting the Mainshill lands before they reach the mossy portion of them adjoining the upper, or compensation, reservoir; the lower, or storing reservoir is seven acres in extent, and has a storeage capacity equal to a supply of 25 gallons to each inhabitant for a period of five months. An extensive system of works for the supply of Calcutta with water are now in course of construction. The supply is drawn from the Hooghly at a point about sixteen miles north of Calcutta, and after being purified is carried by three branches to the Southern, North-eastern, and North-western districts of the city respectively. Railways.-The new line, belonging to the London and Northwestern Railway Company, from Llanrwst to Bettws-y-Coed, has commenced to carry passengers. The new line between Edinburgh and Leith was gone over on the 14th May, and was expected to be opened in about a week from that time. The break of continuity which the Girdle of Paris Railway still presents, between the Batignolles-Clichy goods station and the Courcelles station on the Anteuil line, will soon disappear; the earthworks of the section in question being now nearly completed. The Paris, Lyons, and Mediterranean Railway Company appears to be pushing forward its lines in Algeria with much energy; that from Algiers to Oran is now in progress throughout, and one section-from Relizane to Oran-is expected to be opened for traffic in July. A second line, from Phillippeville to Constantine, is to be completed for traffic in the course of 1869. Upwards of 472 kilomètres of railway are expected to be completed in Italy during 1868. Of these, the Lecce and Zellino line was opened at the commencement of February, and its extension to Otranto has been definitively approved. Mr. Fell's summit-railway over Mont Cenis has certainly not hitherto fulfilled the expectations of its promoters. In May last the Duke of Sutherland went over the line between St. Michel and Susa, a distance of 48 miles, in 4 hours 6 minutes, after deducting the time in stoppages for inspection. The line was opened to the public on 15th June. The concession of a Government guarantee has been given to the Indian Branch Railway Company for its lines in Oudh and Rohilcund, and the extension of the Oudh system is now being proceeded with. The whole distance between Sholapoor and Raichore, on the Madras Extension line, is in course of completion, the rails having now been laid for about fifty miles beyond Sholapoor. On 18th April last the rails of the United Pacific Railroad were laid on the Rocky Mountain summit of the line; according to Bilnkerderfer's survey, the railroad crosses the mountains at this point at an elevation of 8,242 feet, being the highest point reached by any railroad in the world. Bridges.-The North-eastern Railway Company have set resolutely about the replacement of the whole of their numerous wooden viaducts with stone and iron, and in some places with solid embankments. The Hutton, Malton, and Whitby viaducts have been completed, the Ripon is in progress, and the Norton is being filled up. A bridge was recently constructed by the Louisville and Nashville Railroad Company over the Cumberland river, at Nashville, which comprises two spans of 205 feet each in the clear, and a swingbridge, giving two openings, and measuring over 276 feet. A new |