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trifugal pumps, a Venturi meter, and lites and other necessary field instruother apparatus for measuring discharge ments. and frictional losses.

The Electrical Laboratories are supThe Strength of Materials Laboratory plied with power by means of a 20-kilocontains an Emery 50-ton machine and a watt Edison motor, which drives several Riehle 100-ton machine for making tests continuous - current dynamos, series-, in tension, compression, shearing, and shunt-, and compound-wound, bipolar cross-breaking. The latter will take in and multipolar, a Westinghouse experiposts twelve feet long and beams mental alternator, and a rotary converter eighteen feet long. There are also a when used as a polyphase dynamo. Riehle 10-ton universal testing machine; There are also a Crocker-Wheeler directan Olson torsion machine, capable of current motor and a 6-H. P. Edison motwisting shafts sixteen feet in length and tor, used in the mill-room but available two inches in diameter; a Riehle trans- for testing, besides fan motors. Of alverse testing machine; a' Riehle abrasion ternating-current motors, there are a machine; and various types of exten- three-phase and two single-phase inducsometers and micrometers.

tion motors; a special experimental poly




The Cement-Testing Laboratory is phase induction motor of 71/2 H. P., in fitted with the usual moulds and gravi- which the rotor terminals are all separmeters; and contains also a Riehle 2,000- ately accessible ; and a constant-current pound machine for either tension or transformer with a series of six arc compression, another smaller Riehle ma- lamps. The galvanometer room has ten chine for tension only, and an extra large masonry piers to support instruments Faija's hot bath apparatus. In the in such a way as to be free from vibraMetrological Laboratory there are 100- tion. In the Laboratory for Advanced foot and 66-foot standards of length, a Work there is a Kelvin balance and its 10-foot Rogers comparator with grad- rheostat, and an enclosure for experiuating attachment, a Kater's pendulum ments with high voltages. A first-rate with vacuum chamber, a Howard as- collection of instruments, too numerous tronomical clock and electro-chrono- to particularize here, is one of the featgraph, a sidereal chronometer, theodo- ures of the laboratory equipment.

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A Description of the Immense New Dry Dock at Southampton, England,

Now Building for the London & Southwestern Railway


company's estate. The river channel has been deepened by dredging to 30 feet below L. W. O. S. T., thus forming an ample approach. The dock itself will be 860 feet long (clear inside gates ), with

HE NEW GRAVING DOCK now being constructed for the London & Southwestern Railway

Company at Southampton will be the largest of six dry docks belonging to the company, all of which are in constant use. About eight years ago a somewhat smaller dock—but then the largest in the world—was opened by His Majesty the King (then Prince of Wales). Since that time the size and number of vessels frequenting the port of Southampton have been steadily increasing, and it has become necessary to provide more drydock accommodation for vessels of the largest class. Accordingly, towards the end of 1899, the directors of the railway company instructed their consulting engineer, Mr. W. R. Galbraith, M. Inst. C. E., to prepare designs for the present work, the contract for which was let to Messrs. John Aird & Company early in 1901.

The dock will be approached by vessels directly from the estuary of the River Test, which forms one boundary of the

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moreland. The steps and timber slides are also faced with this stone.

The walls are 2212 feet thick at the base, diminishing to 3 feet at the coping level. The floor is flat on its upper surface, but is so constructed on its under

to floor will be 43 feet, giving a flotation depth over keel-blocks of from 29 feet 6 inches, neap tides, to 33 feet, spring tides, at high water.

It is built almost entirely of Portland cement concrete, the floor, altars, and walls being faced with this material. The cement is supplied from the Thames and Medway districts, and an excellent gravel is dredged from Southampton Water, quite near the works. The bulk of the concrete is mixed in the proportion of 8 parts to 1, the facing to walls and floor, together with the culvert linings, being somewhat stronger, generally 4 to 1. A skin of 4 to I concrete is also laid on the under side of the floor, and carried up the back of the walls, so as to prevent any water which may accumulate there from soaking through the more porous concrete into the dock. This 4 to I concrete is made with special care, the large stones in the gravel being reduced in a steam crusher.

The hollow quoins and cill quoins against which the dock gates close, are of granite from the Shap Quarries in West

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the river water at every high tide. The first thing needed was to reclaim the land; and this was done by tipping a horseshoe bank of chalk around the site. This bank was covered with clay to make it water-tight, and pitched with stone to strengthen it. From the enclosure thus

high, being thus very safe and convenient to work on. Access to the floor is given by eight flights of steps, and four slides for timbers are provided.

The entrance gates are being constructed by Messrs. Head, Wrightson & Company, of Teesdale. They are built of steel with greenheart meeting faces, and weigh some 250 tons per leaf. They will be opened and closed by direct-acting hydraulic rams—a somewhat novel principle. The rams are being made by Messrs. Armstrong, of Newcastle.

For emptying the dock, the water will fall into six large pits near the entrance. From these, three tunnels will lead it to the pump wells, which are placed behind the eastern wall and at a level of 10 feet below the dock floor. Over these an engine house is being built, to contain two 48-inch centrifugal pumps, made by Messrs. Gwynne, of Hammersmith. The





formed, the water was thrown out by two pumps, which still work day and night to keep the works dry and safe. Excavation by hand and by “steam navvy” was

next on the programme; and this was CEMENT Mixer At Work.

carried down as low as seemed safe.

Heavily timbered trenches were then pumps will be driven by direct-acting sunk along each side of the dock, and in vertical steam engines, steam being sup- these the massive concrete walls were plied from a battery of seven boilers, of built. It now remained only to excavate the locomotive type, in an adjoining between the walls and build the huge building. This plant is designed to dock floor. This work is being rapidly empty the dock in 21/2 hours if required. pushed forward to completion, piece by

The dock will be fitted with every mod- piece. ern appliance for convenient working. The chief engineer is Mr. W. R. GalNotably, a traveling electric crane is braith, M. Inst. C. E.; and the resident being built for it by Messrs Stothert & engineer is Mr. F. E. Wentworth-Sheilds, Pitt, of Bath, to lift no less than 50 tons Assoc. M. Inst. C. E. The contractors, at 80-foot radius.

Messrs. John Aird & Company, are repTwo years ago the site of the docks resented at Southampton by Mr. J. W. was nothing but a mudland, covered by Landrey.

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