Fortunately some proofs are now at hand, and as the method of getting them has been obtained, more will follow from time to time.
In Engineering, Jan. 17, 1896, Mr. Thomas Andrews, F.R.S., M.Inst.C.E., gives the following cases:
A fracture of a rail into many pieces, causing a serious accident.
A broken propeller-shaft which nearly caused a disastrous accident.
Analysis of the rail:
| Carbon | 0.440 |
| Silicon | 0.040 |
| Manganese | 0.800 |
| Sulphur | 0.100 |
| Phosphorus | 0.064 |
It is clear that the sulphur is excessive, and that it was neutralized so as to make the steel workable by an excess of manganese.
Of the propeller-shaft Mr. Andrews says chemical analysis of outside and central portions of the shaft showed serious segregation.
“The percentage of combined carbon was nearly 50 per cent greater in the inside of the shaft than on the outside; the manganese was also in excess in the inside of the shaft; the phosphorus and sulphur had also segregated in the interior of the shaft to nearly three times the percentage of these elements found near the outside of the shaft.”
Unfortunately Mr. Andrews does not give the analysis of the shaft.