On The Testing And Strength Of Railway Materials, &C.

STEEL . The Admiralty tests at present for steel are as follows : — Tensile and Extension Tests . 1 . Strips cut lengthivise or crosswise of the plate to have an ultimate tensile strength of not less than 26 and not exceeding 30 tons pei square inch of section , with an elongation of 20 per cent in a length of 8 inches . " Tempering Tests . —2 . Strips cub lengthwise of the plate 11- in . wideheated

uni-, formly to a IOAV cherry red , and cooled in water of 82 cleg . Fall ., must stand bending in a press to a curve of ivhich the inner radius is one and a half times the thickness of the plates tested . " 3 . " The strips are to be cut in a planing machine , ancl are to have the sharp ed"es taken off . "

4 . " The ductility of every plate is to be ascertained by the application of one or both of these tests to the shearing or by bending them cold by the hammer on the contractor ' s premises , and at his expense . " 5 . " All plates to be free from lamination ancl injurious surface defects . " 6 . " One plate to be taken for tensile , extension ancl tempering tests from every invoice , provided the number of plates does not exceed fifty . If above that number ,

one for every addition of fifty , or portion of fifty . Plates may be received or rejected without a trial of every thickness on the invoice . " 7 . " The pieces of plate cut out for testings are to be of parallel ividth from end to end , or for at least 8 in . of length . . When the plates are ordered by thickness , their weight is to be estimated at the rate of 40 lb . per square foot for plates of 1 in . thick , and in proportion for plates of all other thicknesses ; the weight so produced is not to

be exceeded , but a latitude of 5 per cent below this ivill be alloAved for rolling in plates of i in . in thickness and upwards , and 10 per cent on thinner plates . These Aveights may be ascertained by weighing as much as 10 tons at a time . ' ' " Tests for Angle , Bulb or Bar Steel . —The whole of the steel to stand a tensile strain of 26 tons to the square inch , and not to exceed 30 tons to the square inch . Also to stand the extension and tempering tests described for plates . All the cross ends are to be cut off . One bar is to be taken for testing from every invoice , providing the number of bars does not exceed fifty ; if above that number , one for every additional fifty , or portion of fifty . "

STEEL TESTS . As the result of the report on steel for shipbuilding of the chief surveyor of Lloyd's , Mr . B . 'Martell , ancl his assistants , Messrs . Cornish and John , give the following , Avhicli is portion of a notice issued by Lloyds on the 1 st Nov ., 1877 . The steel to be used in ships building for classification in the register book will he required to stand the folloAving tests ; to be applied under the personal inspection of the

the surveyors to the society , to samples selected by them whenever deemed by them to be desirable . Tests . —Strips cut lengthwise or crossivise of the plate , and also angle and bulb steel , to have an ultimate tensile strength of not less than 26 , and not exceeding 30 tons per square inch of section , with an elongation of 20 per cent before fracture . Strips out from the angle or bulb' steel to be heated to a IOAV cherry red , and cooled in water of i > 2 cleg . Fah ., must stand bending double round a curve of ivhich the diameter is not mow than three times the thickness of the plates tested .

TEST FOE BESSEMER STEEL KAILS . Rails Avill be taken from each day ' s rolling and placed upon bearings 3 feet apart ; Avhen a ball weighing 10 civt . is to be raised 10 feet and dropped three times , Avheu the deflection must not exceed 3 inches . TESTING RAILWAY STEEL AXLES . As is generally known , the mode of procedure usually adopted by continent raihvay engineers s to take one out of each hunched axles and test it to destruction , h