full firing, for at least 20 minutes with the feed-water shut off and stopvalve closed. In cases where valves of similar design have been previously approved and passed by the Board of Trade, and the Surveyors are fully satisfied with the result of the test under full steam, they need not delay the granting of the declaration for the vessel subject to approval of the Board, care being taken that full particulars of the valves and tests are forwarded to the department by the same post as that by which the declaration is transmitted to the owners. If the accumulation of pressure exceed 10 per cent. of the loaded pressure, he should not give his declaration without first reporting the case to the Board of Trade, accompanied by a sketch, and full particulars of the trial and the strength pressure of the boilers. In the case of valves, of which the principles and details have already been passed by the Board of Trade, the Surveyor need not require plans to be submitted so long as the details are unaltered, of which he must fully satisfy himself; but in any new arrangement of valves, or in any case in which any detail of approved valves is altered, he should, before assuming the responsibility of passing them, report particulars with a drawing to scale, to the Board of Trade. He can make this drawing himself from the actual parts of the valves fitted, but in order to save time and to facilitate the survey, the owners or makers of engines may prefer to send in tracings of their own before the valves are placed on the boiler. If they do this the survey can be more readily made, and delay and expense may be saved to owners, as the Surveyor will not then have to spend his time and delay the ship in preparing drawings and comparing them with the valves. The tracings of new safety-valve designs should, if possible, be transmitted to the Board of Trade for consideration before the construction of the safety-valves is commenced. In some spring valves the accumulation of pressure has reached cent. per cent., and therefore if the Surveyor had not required a trial he would have passed valves which would have caused a pressure on the boiler double that intended by him. And in some cases in which the increase of pressure has not been great, defects that would have rendered the valve highly dangerous have been discovered on an examination of drawings. The Surveyors should arrange with manufacturers so that the Survey ors may have the designs of valves which the manufacturers intend to use. An easy method of facilitating this matter is for the manufacturer to leave in the local Surveyor's office a plan or plans of his valve or valves when once agreed to, and then afterwards to inform the Surveyor that the valves fitted are according to drawing A, B or C, as the case may be. By this means, when once a design has been agreed upon, and is adhered to, all subsequent questions and delays will be prevented. The following is a list of the names of spring safety-valve makers whose standard designs have been approved by the Board of Trade:* NOTE.-Any departure from designs should be reported to the Board for consideration. 82. It is clearly the duty of the masters and engineers of vessels to see, in the intervals between the surveys, that the locked-up safety-valves, as well as the other safety-valves and the rest of the machinery, are in proper working order. There is no provision in the Merchant Shipping Act, 1854, exempting the owner of any vessel, on the ground that she has been surveyed by the Board of Trade Surveyors, from any liability, civil or criminal, to which he would otherwise be subject. The Act of Parliament requires the Government safety-valves to be out of the control of the engineer when the steam is up; this enactment, far from implying that he is not to have access to them, and to see to their working, at proper intervals when the vessel is in port, rather implies the contrary, and the master should take care that the engineer has access to them for that purpose. Substantial locks that cannot be easily tampered with, and as far as possible weather-proof, should be used for locking up the safety-valve boxes. 83. In witnessing the hydraulic tests of boilers, etc., and in witnessing all safety-valve tests for accumulation of pressure, the Surveyors are to use the pressure gauges supplied by the Board of Trade for the purpose. The steam gauge should not be used without a syphon filled with water between it and the boiler. PART IX. UNITED STATES GOVERNMENT RULES FOR THE INSPECTION OF THE BOILERS OF STEAM VESSELS. THE FOLLOWING IS TAKEN FROM THE GENERAL RULES AND REGULATIONS CIRCULAR OF THE U. S. BOARD OF SUPERVISING INSPECTORS OF STEAM VESSELS. The following is taken from the "General Rules and Regulations" circular of the U. S. Board of Supervising Inspectors of steam vessels: 1. Every iron or steel plate intended for the construction of boilers to be used on steam-vessels shall be stamped by the manufacturer in the following manner: At the diagonal corners, at a distance of about four inches from the edges, and at or near the center of the plate, with the name of the manufacturer, the place where manufactured, and the number of pounds tensile strain it will bear to the sectional square inch. 2. Whenever inspectors shall find a plate of iron or steel with stamps differing as to the tensile strength of the material, they shall rate the tensile strength of the same in accordance with the lowest stamp found thereon. 3. To ascertain the tensile strength of plates, a piece shall be taken from each sheet to be tested, the area of which shall equal one-quarter of one square inch on all iron inch thick and under; and all iron over inch thick the area shall equal the square of its thickness; and the force at which the piece can be parted in the direction of the fibre or grain, *represented in pounds avoirdupois-the former multiplied by four, the latter in proportion to the ratio of its area-shall be deemed the tensile strength per square inch of the plate from which the sample was taken; and should the tensile strength ascertained by the test equal that marked on the plates from which the test-pieces were taken, the plates must be allowed to be used in the construction of marine boilers: Provided always, that the plates possess homogeneousness, toughness, and ability * This means that the force is to be applied endways of the grain. 221 to withstand the effect of repeated heating and cooling; but should these tests prove the plates to be overstamped, the lots from which the testplates were taken must be rejected as failing to have the strength stamped thereon. But nothing herein shall be so construed as to prevent the manufacturers from restamping such plates at the lowest tensile strain indicated by the samples, provided such restamping is done previous to the use of the plates in the manufacture of marine-boilers. 4. Local inspectors are required to make and send to the supervising inspectors, with every sample of iron or steel to be tested, their certificate that the sample sent for testing was cut from the plate or plates to be used in the boiler designated. And the manufacturer of any boiler to be used for marine purposes shall furnish the inspectors an affidavit in the following form, subscribed to either by himself or authorized agent, having superintendence of the construction of such boiler: Affidavit of manufacturer of marine steam-boilers. COUNTY OF- On this day of me, a notary public in is Mr. of ss: A. D. 188-, personally appeared before and for the county of — and State of who, being duly sworn, deposes and says that he boiler manufacturer, and that the accompanying manufactured by were cut from -T. S., which are to be used in the construction of and no plate of less tensile strength or quality than herein specified will be used in the construction of said boiler, the samples of plates stamped a marine boiler for dimensions of which will be of be used upon the steamer Sworn and subscribed to before me, this day of 188-. Notary Public. 6. To ascertain the ductility and other lawful qualities, iron of 45,000 pounds tensile strength, and under, shall show a contraction of area of fifteen per cent., and each additional 1,000 pounds tensile strength shall show one per cent. additional contraction of area, up to and including 55,000 T. S. Iron of 55,000 T. S. and upwards, showing twenty-five per cent. reduction of area, shall be deemed to have the lawful ductility. All steel plate of one-half inch thickness and under shall show a contraction of area of not less than fifty (50) per cent. Steel plate over one |