reased as much as 70 to 80 per cent. Whereas superior iron chains
break at a strain at 17 tons per square inch, these weldless steel
chains will stand a strain of 28 to 30 tons, with 20 to 26 per cent.
elongation.

[Illustration: Figures 1. Through 9., 1_a_, 1_b_ and 3_a_
MANUFACTURE OF WELDLESS CHAINS.]

Again, there is greater security in their use from the fact that there
are no welds, and they give warning of the limit of strain to which
they can bear being approached, by elongation, which can be carried to
a considerable extent before the chain breaks. Moreover, over, in
chains made by this process, the links are all exactly alike. Though
the life of a weldless steel chain is said to be twice that of an
ordinary one, the price per length is little more than that of best
iron chains.

They are made in lengths of from 40 to 50 feet, being compressed from
a solid rolled steel bar, the section of which is shaped like a
four-pointed star. In the first place holes are pierced at intervals
down the length of the bar, thus determining the length of the several
links. Then the bar is notched between the holes so as to give the
external form of the links. The next step is "flattening out," which
presses the links into shape on their inner side, but leaves the
openings still closed by a plate of metal. They are then stamped out
so as to round them up, and the metal inside them is punched out, and
the edges "cleaned," or trimmed off. The links are now parted from one
another and stamped again, to insure equal thickness in all parts of
the chain. The only processes now to be gone through are dressing and
finishing. According to the die used, the shape of the links can be
varied to suit any required pattern. The lengths of chain thus made
are joined by spiral rings made of soft steel, the convolutions being
afterward hammered together till they become solid. A ring of this
description, 3/4 inch diameter, underwent a strain of 46,200 lb., that
is, 23 tons to the square inch, its elongation being 21 per cent.

These chains have passed satisfactorily the tests of the Bureau
Veritas, and both that association and Lloyd's have accepted their use
on the same conditions and under the same tests as ordinary chains.

So much for the general idea of punching steel chains. We will now
describe a recent invention by which superior steel chains are
produced, the author of which is Mr. Hippolyte Rongier, of Birmingham,
En