The Locomotive - Lighthouse Survival Blog
The Locomotive - Lighthouse Survival Blog
The Locomotive - Lighthouse Survival Blog
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20 THE LOCOMOTIVE. [February,<br />
could be iuferred with considerable precision. It will be impossible to give the results<br />
of these tests in detail in this place, but the foregoing abstract of five of them shows<br />
quite well that the strength of steel is greater at about 500° Fah. than it is at 70°. <strong>The</strong><br />
temperatures are all on the Fahrenheit scale.<br />
<strong>The</strong>se five series of tests were made with five difl^erent qualities of steel, containing,<br />
respectively, .09, .20, .31, .37, and .51 per cent, of carbon. <strong>The</strong> figures given in the<br />
columns headed "Percentage of Strength" were obtained by dividing the tensile<br />
strength of a samj^le of steel at the given temperature by the strength of the same quality<br />
of steel at 70° Fah.<br />
:<br />
It will be seen that these specimens were all stronger in the neighborhood of zero<br />
than they were at ordinary temperatures; and that, in fact, they all show a minimum of<br />
strength at 210°, or thereabouts, and a maximum of strength at about 550°. This<br />
curious property of iron may now be considered to be well established ; and it deserves<br />
further attention than it has yet received.<br />
Inspectors' Report.<br />
November, 1892.<br />
During this month our inspectors made 6,013 inspection trips, visited 12,457 boilers,<br />
inspected 4,621 both internally and externally, and subjected 714 to hydrostatic press-<br />
ure. <strong>The</strong> whole number of defects reported reached 9,952, of which 1,029 were considered<br />
dangerous ; 40 boilers were regarded unsafe for further use. Our usual summary<br />
is given below<br />
Nature of Defects.<br />
Cases of deposit of sediment.<br />
...<br />
-<br />
Cases of incrustation and scale,<br />
Cases of internal grooving, ...<br />
....<br />
Cases of internal corrosion, - - -<br />
Cases of external corrosion,<br />
Broken and loose braces and<br />
....<br />
stays, -<br />
Settings defective, - . . - -<br />
.....<br />
Furnaces out of shape,<br />
Fractured plates, - . . - -<br />
Burned plates,<br />
...<br />
Blistered plates, . . . . -<br />
Cases of defective riveting, - - - -<br />
Defective heads, . . . - -<br />
Serious leakage around tube<br />
....<br />
ends,<br />
Serious leakage at seams,<br />
Defective water-gauges,<br />
....<br />
Defective blow-offs, . . _ .<br />
Cases of deficiencj' of water, . . -<br />
Safety-valves overloaded,<br />
Safety-valves defective in construction.<br />
Pressure-gauges defective, . . . -<br />
Boilers without pressure-gauges, . - -<br />
Unclassified defects, . . - - .<br />
Whole Number.
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