Osbert Chadwick Esq., C.M.G.
4/12/1906.
The amount of Slag in samples No. 1 & No. 3 differs considerably, but is to be expected in metal of this sort. The amount of Phosphorus in samples No. 1 & No. 3, although considerably higher than in the standard analysis, is well within the ordinary limits for Wrought Iron. There is nothing abnormal in the figures of the two analyses.
Microscopical examination of 5" Pipe (Sample No. 3).
18.
This Pipe had burst longitudinally through a length of 12 inches. At the screwed end, which had been supported by a socket, the fracture terminated in a fine single hair crack; at the other end the crack was forked.
19.
With a view to ascertaining the relative position of slag to the fracture, and whether such slag was in sufficient quantity to unduly weaken the metal at this point, sections were cut, polished and etched:
(a) At the screwed end of the Pipe. This section contained the extreme end of the crack.
(b) At the opposite end about two inches from the end of the crack.
(c) At the weld.
20.
The examination of these specimens under the microscope revealed the slag to be distributed throughout the metal in a somewhat irregular manner. The slag formed longitudinal strings of appreciable width, and of a length of about 1 inch. No exceptional length or width of slag could, however, be detected in the neighbourhood of the fracture. The weld was examined and found to be sound and free from slag, and to extend over a length of about 1 inch of the circumference of the Pipe, and to be therefore a lap weld as specified in the Contract. It was about 3 to 4 inches from the fracture. From the above microscopical examination there is no evidence as to the cause of
249
Osbert Chadwick Esq., C.M.G.
4/12/1906.
The amount of Slag in samples No. 1 & No. 3 differs considerably, but is to be expected in metal of this sort. The amount of Phosphorus in samples No. 1 & No. 3., although considerably higher than in the standard analysis, is well within the ordinary limits for Wrought Iron. There is nothing abnormal in the figures of the two analyses.
Microscopical examination of 5" Pipe (Sample No. 3).
18.
This Pipe had burst longitudinally through a length of 12 inches. At the screwed end, which had been support- ed by a socket, the fracture terminated in a fine single hair crack; at the other end the orack was forked.
19.
With a view to ascertaining the relative position of slag to the fracture, and whether such slag was in sufficient quantity to unduly weaken the metal at this point, sections were out, polished and etched:
(8)
At the screwed end of the Pipe. This section
contained the extreme end of the crack.
(b)
At the opposite end about two inches from the
end of the crack.
(e)
At the wela,
20.
The examinetion of these specimens under the microscope revealed the slag to be distributed throughout the metal in a somewhat irregular manner. The slag formed longi- tudinal strings of appreciable width, and of a length of about 1 inch, No exceptional length or width of slag could, however, be detected in the neighbourhood of the fracture. The weld was examined and found to be sound and free from slag, and to extend over a length of about 1 inches of the circumference of the Pipe, and to be therefore a lap weld as specified in the Contract. It was about 3 to 4 inches from the fracture. From the above microscopical examination there is no evidence as to the cause of
249
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