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asks me whether my attention has been called to the conviction of a shipowner against whom I myself directed a prosecution for sending a dangerously-rotten ship to sea. As regards any further precautions having been taken, the same arrangements still exist at Cardiff as existed when the Alcedo was detained under them. As to the supposed loss of the Alcedo and her crew, the Alcedo was not lost, but remains at Cardiff, where she was detained, and has been, or will be, broken up.-Sir CHARLES ADDERLEY said, in reply to Mr. MACIVER, that the Nimrod and Alcedo were both detained in port as unseaworthy, were both condemned, and the owners of both were convicted, fined, and imprisoned. I think that Section 11 of the Merchant Shipping Act of 1871 should be strengthened, and there was a clause in the Government Bill for that purpose. But I think the indirect operation of that clause has been effective in the way of deterring people from sending unseaworthy ships to sea. It is true that the only convictions yet obtained under the 11th Section of the Act of 1871 are those of the owners of the Nimrod and Alcedo, and, of course, in cases where ships go to the bottom evidence can rarely be obtained; but the principle of the law is to convict offenders, and not to anticipate offence by inspecting all. No one doubts that there are unseaworthy ships, and probably more than have been detected, but the Board of Trade has successfully hit many, and has very successfully avoidel involving the innocent in its prosecutions.

Public Prosecutor, Thursday, August 5th.-In answer to Sir E. WILMOT, Mr. CROSS said that the subject of the appointment of a Public Prosecutor had been long under his consideration, and he was anxious to bring it to a successful termination. He could not give any pledge, or make any distinct promise, as to next Session, but he would lay on the table some correspondence on this subject which was carried on during the time when his predecessor was in office.

Merchant Shipping, Friday, August 6th.—Mr. REED, on behalf of Mr. PLIMSOLL, gave notice that next Session he would move for a Select Committee to inquire into the subject of marine insurance, to investigate the state of the law thereon, and to report if any and what changes were desirable; that he would introduce a Bill to extend to merchant seamen whose vessels were within five miles of the coast-line of the United Kingdom the provisions of the Employer and Workmen Act, which abolishes imprisonment for breach of contract; and that he would move for a Committee to inquire into the manner in which the Unseaworthy Ships' Act, 1875, and previous Acts relating to Merchant Shipping, had been administered by the Board of Trade, and into other matters concerning that department.

British Vessels under Foreign Flags, Monday, August 9th.-Sir CHARLES ADDERLEY stated, in reply to Mr. NORWOOD, that the number of British

vessels transferred to foreign flags, since the 1st of January, 1873, was 875.

Unseaworthy Ships, Wednesday, August 11th.-Sir CHARLES ADDERLEY, in reply to Mr. REED, said the question incorrectly assumes that there were not more than two prosecutions under the 11th Section of the Act of 1871. With reference to the 515 cases mentioned, the chief reason why more prosecutions have not been made is that the Section only provides for cases in which the owner or others actually send a ship to sea in an unseaworthy state. The Board of Trade have, under the 12th Section of the Act of 1873, stopped ships from going to sea, thereby intercepting the offence which would come under the 11th Section of the Act of 1871. There was a clause in the dropped Merchant Shipping Bill which had been passed in the Unseaworthy Ships' Bill, elaborated and improved by the hon. member for Durham, by which the Board of Trade will be empowered to proceed against persons who attempt to send or take unseaworthy ships to sea. This, with improved legal machinery, will probably make the law much more effective in future.

Burning of the "Cospatrick," Wednesday, August 11th.-In answer to Mr. HAYTER, Sir CHARLES ADDERLEY said the Court which inquired into the loss of the Cospatrick by fire made three recommendations-1. That bulkheads in wooden ships should be made to separate the forepeak, as in iron ships the collision bulkhead does. This has been already attended to. 2. That some better regulation should be made in emigrant ships as to the stowage of boats, and that they should not be stowed on board keel upwards. This has been referred to a Departmental Com mittee, whose labours have been delayed by the illness of Captain Forster, the chief emigration officer of the Board of Trade. 3. That a boat drill should be established in all emigrant ships. This has been recommended to shipowners by a circular, but it is not a matter that could be dealt with imperatively by order or by legislative enactment.

Prorogation of Parliament, Friday, August 13th.-Parliament was prorogued by Royal Commission, after the reading of the usual Royal Speech, until the 29th of October next.

DIRECT ACTING SPRING SAFETY-VALVE,

ON THE MECHANICAL PROPORTIONS AND GEOMETRY EMBODIED IN THE CONSTRUCTION OF A DIRECT ACTING SPRING SAFETY-VALVE, AND ON CERTAIN PHENOMENA ATTENDING THE BEHAVIOUR OF THE STEAM AT AND ABOUT THE ESCAPING ORIFICE.

HERE are five essential elements appertaining to a safetyvalve worthy of the name it bears.

1st. That under no conditions, whatever, of the fires, should the pressure rise in the boiler above that due to the

load placed on the safety-valve.

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2nd. The relieving power of the valve should be twice the generating power of the fires.

3rd. The valve should return to its seat with the least practical loss of pressure.

4th. It should perform its work in the least possible amount of time, and

5th.--It should be perfectly automatic.

To fulfil the above conditions, the valve, Fig. 1, has been designed. F is the flange which fits the top of the boiler. A is the opening to the boiler, and in common communication with both valves. V is the valve and S the head of the seating thereof, by the geometrical outlines of which the surrounding chamber C is formed. D is a division cast in the box separating the upper part of a pair of valves, the design of which is to prevent the waste steam escaping from the valve which blows off first, from exerting its influence on the top of the other, and so prevent its neighbour from rising. W are two waste passages leading from the box, which are connected to the waste-pipe by a breeches-piece. H is a collar cast on spindle, and at a distance from B equal to one-fourth the diameter of the valve. B is a brass bush in the base of the column enclosing the spring, and L is a small weight resting on B, to prevent water or dirt passing through beside the spring. P is a pintle resting en a shoulder on the spindle, and on which the bottom end of the spring rests, the barrel of which is continued up inside the spring, but stopping at a distance from the top of it equal to one-fourth the diameter of valve, when the load is on the spring. The design of the pintle is to prevent the spring moving from its place in case of breakage, for should this spring break, the broken ends cannot pass each other, because the spring cannot move laterally to any point of the compass whatever, but is held in its position in all directions by the pintle, and the ship would come home and no person on board would know that there was a broken spring. Supposing the spring to break in the middle of its length, and the distance between the coils to be one-eighth of an inch, then the top end would descend a sixteenth, and the bottom end would ascend a sixteenth of an inch, and the mean fall or shortening of the spring in its centre line would be a sixteenth of an inch. Let the deflection of the spring with the load upon it be 14", equal to 24-sixteenths, and let the original load on the valve be 60 lbs., then =2 lbs. equal the reduced pressure at which the valve would blow off. So that instead of the valve blowing off at 60 lbs. as before the break, it would blow off at 571⁄2 lbs. after the break, and this is all the difference between a whole and a broken spring, and it could only be by close observation of the engineer that he could tell whether he had a whole or a broken spring on board, the 24 lbs.

earlier blow off being his only means of discovery. N is a brass nut with a fine thread on it and a hexagonal top with which to screw it down; and R is a distance piece, the size of which is taken when the proper load is on the spring. K is a cotter, through the point of which the padlock passes. H' is a cross-head, the lower end of which is let into a brass bushed cap to a depth equal to half the diameter of the valve, and with two collars, between which the forked end of the easing lever L fits, and with two handles with which to turn the valve on its seat in case of dirt getting between the faces, both valves being so fitted.

ON THE GEOMETRY EMBODIED IN THE CONSTRUCTION OF THE SPRING. Fig. 2.-Let A O be any straight line produced through G indefinitely. On A set off the isoceles triangle B A C, such that the angles BA O, CA O, contain each 7° (correctly it is 7° 40'). Select any point O in A G, join B C, so that O B and O C are each at right angles to A G. Set off O B into three equal parts, of which O H is equal to two parts, on O as a centre. With OH as radius, describe the semicircle EGH. On G as a centre with the same radius, set off the arc G E equal to 60°, draw the lines E O, ED, E F. E D is the sine of the angle D O E, and is equal to the side of the square of steel of which to make the spring. And E F is the cosine of the angle D O E, and is equal to the pitch C C', and E F will divide O A into 13 equal parts, equal to 13 complete coils and the ends. And the angle B A C is the angle of stability of the spring, and contains 15°. And all springs constructed on this principle, whether of a 16-inch wire, or of a 6-inch bar of steel, are each proportional to one another, and if the results obtained from one be good, the others must be good also. They are also all unbreakable. The standard spring, from which the author has made his experiments and calculations, is made from a "square bar of the best cast steel and contains 25 of a square inch. The spring is 2" inside diameter, 3" outside diameter, Hos 13 complete coils and the ends, and is 11" long. The working load on this spring is 600 lbs., being one-sixth part of its breaking load when hardened to a temper just sufficient to break it, and the load deflects the spring exactly one inch, so, that when the load is on, the spring is 10" long.

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