banking institution, with the object of supporting trade in bad times, by granting loans to the iron proprietors at low rates, on stocks of iron which could not at the time be realised advantageously. The funds for this Institution were and are now obtained by levying a small rate on production, and the total funded capital is about £300,000. The iron trade of Sweden is assisted in addition by a considerable staff of engineers, mining, metallurgical, and mechanical, mainly supported by the Jernkontor. The country is divided into mining districts, with a director and engineer for each, and a few articled pupils, all receiving a yearly salary from the Jernkontor, and allowed to charge the ironmaster a small settled fee when employed in the construction of new works, or in the introduction of new processes. The staff have received a course of scientific and practical education at the government School of Mines, and they are often sent to foreign countries, in order to keep the ironmasters informed of what is going on abroad. For the last forty or fifty years the "Jernkontor" has published a journal, called the "Jernkontorets Annaler," containing mainly the annual reports of each of these employés. It is now ably edited by Professor Richard Åkerman, of the Royal School of Mines in Stockholm, and is sent gratuitously to all the ironmasters in Sweden, but is obtainable by the public at a low cost. The Jernkontor is governed by a president, vice-president, and ten councillors, who are elected every third year; their meetings are held every quarter in Stockholm, where the permanent secretary and treasurer conduct business in the intervals between the meetings.

It would be unjust to finish this description of Swedish engineering without acknowledging that the credit mainly belongs to the Corps of Royal Engineers for the construction both of the canals and of the railways. The country is divided into districts in respect of road and water communications, and each district is provided with officers to survey and execute public and private works. Members of the Corps of Royal Engineers are previously educated at the Government School of Civil and Military Engineers at Marieberg, near Stockholm, and afterwards have to execute both private and public works as well as inspect them before they are opened. A yearly report is submitted to Parliament of work done in each district. This formerly consisted in canal-making, drainage of lakes, building of harbours and docks, and new roads, for which Government generally defrays part of the cost.

Railways have advanced to such an extent in Sweden, that the Corps has of late been too much occupied to give a detailed de

scription of work done; the reports have in consequence been complained of as short and uninstructive. There being no special department of Government for public works, railways, canals, and mining engineering come under the control of the Minister of the Interior. With the increase in construction of railways and public works generally, there is thought to be a necessity for a Department of Public Works, similar to like branches of the Government in other countries, to regulate the construction of new lines as well as the working of those open, to promote industry, and to serve as a guarantee for public safety. Should such a department be established, nothing would be of greater assistance to the engineering profession in that country, and particularly to the Civil Engineers, who may now be considered as a body without a chief.

No. 1,401. The Implements employed, and the Stone Protection adopted, in the Reconstruction of the Bridges on the Delhi Railway." By CHARLES STONE, M. Inst. C.E.

IN 1867, when in charge, for the Company, of the Jumna bridge works, Delhi Railway, the Author commenced making notes with a view to write an account of the system of well-sinking then in progress. Finding, however, Mr. Imrie Bell, M. Inst. C.E., who represented the contractors at that time, and who was daily employed in superintending the practical working, similarly engaged, the idea was given up, in the belief that his Paper would be the more valuable one. Since then the unusually heavy floods of 1871-2 have caused serious disasters to the bridges, scouring out many of the well piers and of the wells of wing walls, although the former were sunk to depths of from 40 feet to 43 feet, and the latter to depths varying from 26 feet to 43 feet, below low water, indicating that those depths were insufficient, unless the foundations were protected by beds of stone, to prevent or reduce the scour. This has been successfully carried out, new well piers have been sunk to an increased depth, and protected with stone, and training bunds have been put in for conserving the rivers above bridge for the protection of the abutments.

The Author now desires to supplement Mr. Bell's Paper, with an account of the various implements used in the reconstruction works carried out under his supervision at the Sutlej, Beas, and Jumna rivers, and with a description of the system of stone protection adopted at all large rivers and streams subject to floods, crossed by the Delhi railway, as well as of the training banks put in for preserving the channels above bridge,—a system which, from the experience gained, is being universally followed by the Engineers of the State railways.

It was decided to sink the new piers for the bridges over the rivers Beas and Sutlej to a depth of 70 feet, if possible, below low water, and to increase the diameter from 12 feet 6 inches to 15 feet; but to reduce that diameter to 12 feet 6 inches at low-water level, so as to correspond with the other piers of the bridge. The first well curbs, of 12 feet 6 inches diameter, were of iron; those

1 Vide Minutes of Proceedings Inst. C.E., vol. xxviii., p. 325.

used in the reconstruction works were of wood, in sections or rings, so as to break joint, and dowelled together.

The system of sinking with the jham and sand pump has already been described by Mr. Bell. From the increased diameter of the cylinders, and the increased depth, the sand pump alone was found insufficient for the purposes, owing to the stiff clay and conglomerate met with at from 30 feet to 35 feet below low water. Accordingly the sand pump has been superseded, to a considerable extent, by Bull's dredger' (Plate 12, Figs. 1 to 4), used in sinking the new wells of the above bridges. The dredger is lowered into the well by a crab and tackle working over a pulley fixed to a gallows or sheer-legs, erected on a stage at the top of the well. Before lowering, the clip or double pin (Fig. 4) is inserted into holes in the two segments (Fig. 2); this keeps the dredger open until it reaches the bottom of the well, when the clip is withdrawn by means of a stout cord. The lowering chain, attached to the chains working in guides and small rollers at the four corners of the dredger, is then pulled up slightly, agitated, and lowered by coolies. By these means the jaws of the dredger are gradually drawn together, scooping up the sand or loose material. The number of times the chain is so pulled depends upon the material to be dredged. With loose soil the jaws soon meet, when the dredger is drawn up, opened on the staging, and the materials fall out; the clip is then again inserted, and the operation repeated. In sand, the time occupied for each operation of lowering, dredging, and lifting averages five or six minutes; the depth in this case being, from the top of the staging to low water 25 feet, from low water to the bottom of the curb 46 feet, the depth of hole dredged below the curb 12 feet, or a total of 83 feet. With the sand pump a corresponding operation would take more time, as the four cotters have to be driven out when the pump is dropped on to the staging, the pump raised to leave the bottom clear to remove the sand, and then lowered and re-keyed. So long as the material is sand the dredger is effective; but, like the pump, it can only be lowered into the centre of the well, and the result is that, in stiff material, the dredger works out a hole in the form of an inverted cone, and the quantity dredged at each operation is small.

In the stiff clay and conglomerate met with at the Sutlej at a depth of about 35 feet, the progress of sinking was exceedingly

1 An account of this and of other excavating apparatus is contained in "Professional Papers on Indian Engineering," 2nd series, vols. i., ii., and iii. passim.

slow. The Author then tried a jumper, composed of rails fished together for the required lengths, the end of the lower length being chiselled to an edge. This jumper was raised by a crab engine or by coolies to a height of 8 feet or 10 feet, then suddenly let go, when the jumper became imbedded deeply in the clay. The operation was repeated until a sufficient quantity had been loosened, when the dredger was used, bringing up masses weighing from 20 lbs. to 85 lbs. This combined system, of the heavy chiselled jumper and the dredger, has been found the most suitable for great depths and stiff material. One advantage of the chiselled jumper is that, when raised to the required height, it can be 'guyed' over and dropped at any point within the well. But after excavating, by these means, to a depth of 16 feet below the bottom of the curb, notwithstanding the wells were loaded with rails and other iron material to the extent of from 700 tons to 800 tons, the wells would still hang. Divers were then sent down to excavate under the curb; and after dredging out the stuff so cut away, and exhausting the water to within 8 feet of the bottom, the wells seldom sank more than 1 inch at a time. In the wells recently sunk at the Sutlej, the soil was so dense that an average depth of only 2 feet 10 inches was attained for each well, after working in the way above described for three months.

The wells were filled with concrete by ordinary skips. To accomplish this, to build up the piers from low-water level, and to lay the girders before the floods came on, it was necessary to suspend operations at a depth of 47 feet below low water. But as probings showed that there was a stiff bed of clay and conglomerate for at least 15 feet below the bottom of the curb, and as the wells were protected by 20,000 cubic feet of heavy blocks of stone thrown in round them, it was believed they would not be injured by scour.

An excavator for deep well foundations has been introduced by Mr. R. J. Ives, a sub-engineer in the Public Works Department, which he believes will supersede sand pumps and dredgers, at all events for stiff clay. Figs. 5, 6, and 7 (Plate 12) represent the tool as adapted for clay, Figs. 8 and 9 as applied for sand. The mode of working is as follows: The excavator lock, at the back, is first pushed into place, a light line being attached to the lock, as shown. The blade is now open or vertical with the monkey guide rod, in which position the excavator is lowered to the bottom of the well, where the apparatus is kept upright by the lowering-chain being held slightly taut. The monkey is now worked up and down the centre guide rod, by the line attached to