Thus the limits of the Chapin iron are from 12 to 20 per cent. above
those of refined iron, and not far below those of structural steel,
while there is a saving of some four dollars per ton in the price of
the pig iron from which it can be made. When made from the best pig
metal its breaking and elastic limits will probably reach 70,000 and
40,000 pounds respectively. If so, it will be a safer material than
steel under the same working strains, owing to its greater resilience.

Such results are very interesting in both a mechanical and economical
point of view. Engineers will hail with delight the accession to the
list of available building materials of a wrought iron at once fine,
fibrous, homogeneous, ductile, easily weldable, not subject to injury
by the ordinary processes of shaping, punching, etc., and having a
tensile strength and elastic limit nearly equal to any steel that
could safely be used in the same situation.

A plant for the manufacture of Chapin iron is now in course of
erection at Bethlehem, Pa., and there is every reason to believe that
the excellent results attained in Chicago will be more than reached in
the new works.--_Proceed. Jour. Asso. of Eng. Societies_.

* * * * *




CELLULOID.


Professor Sadler, of the University of Pennsylvania, has lately given