ve unsatisfactory results in
wear, than those from the latter; but as the test pieces are usually cut
from the center of the railhead, the tensile resistance of the interior
may be equal to or surpass that of the superior material. In summing up
his observations the author concludes that the method of tensile testing
is mainly of value in determining the quality of the material, but that
for the finished product properly arranged falling weight tests are
necessary. He also considers that the test pieces should be flat bars of
2.5 to 3.5 centimeters in area, cut as near as possible to the outer
surface of both head and foot of the rail. He reprobates especially the
research for microscopic imperfections (mikrobensuecherei) upon the
fractured surfaces, as an annoyance to the producer, and perfectly
useless to the consumer.--_Stahl und Eisen_, vol. iv., page 608; through
_Proc. Inst. Civ. Eng_.
* * * * *
A NEW FORM OF SMALL BESSEMER PLANT.
By Mr. A. TRAPPEN.
The success of the Bessemer process when carried out on the small scale
at Avesta in Sweden, as described by Professor Ehrenwerth, and subsequent
experiments of a similar kind made at Pravali, in Carinthia, and
elsewhere, have led the author, who is specially occupied in the building
of Bessemer works, to design a plant suitable for operation upon small
charges. This consists essentially of a converter about 1 meter outside
diameter, and 1.5 meters high, connected by a single trunnion to a
horizontal steel shaft carried by the arm of a hydraulic crane which is
very similar in character to the ladle crane of a large sized converter.
The sweep of the crane is such as to allow the converter to be brought
close up to the tap hole of the blast furnace or cupola, so that the use
of open gutters for the fluid metal may be avoided as much as possible.
The converter is turned on its axis by a screw and worm wheel, which is
manipulated by a workman standing on a platform at the opposite arm of
the crane. The blast is brought in from above by a pipe down the central
pillar of the crane, which is connected with the blast-main by a flexible
tube and packed joint. The outer trunnion bearing is open, so that by
slightly raising and lowering the ram of the crane, the converter may be
left suspended to a weighing machine in front of the furnace, if it is
required to determine the weight of the charge. When the converter is
filled, it is bo
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