This crane is worked by eight men, and readily lifts
burdens of about 200,000 lb. The other engraving shows the jack frame and
jacks employed to remove the gun from the temporary truck. At a range of
7,000 yards these guns are able to penetrate iron plates of two feet
thickness.
* * * * *
QUALITATIVE TESTS FOR STEEL RAILS.
By Mr. L. TETMAJER.
This memoir is the first of a series upon the unification of nomenclature
and classification of building materials, undertaken by the author at the
request of the Swiss Engineers' and Architects' Union. For its
preparation numerous mechanical tests have been made upon steel rails,
both good and bad, taken from the Swiss railways, while the corresponding
chemical analyses have been made by Dr. Treadwell in the Polytechnic
Laboratory, at Zurich. The results are given for twenty-two examples,
about one-half of which have stood well, while the remainder have either
broken, split, or suffered considerable abrasion in wear; but in many
instances the mechanical test of tensile strength, elongation, and
contraction, and the figures of quality (Wohler's sum and Tetmajer's
coefficient) deduced from these have varied very considerably for the
results obtained in practice.
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