The Sun.
London, England, 1849-06-07 00:00:00

X 640

INSTITUTION OF CIVIL
ENGINEERS.
• Tuest%y, June 5, 1549.
• Joshua Field, E• q., President, in the Chair.
The paper read was a " Description of a Method of
Rolling Bars for Suspension Bridges, and other like
, Purpoties," by Mr. Thomas Ho vard, Assoc. lasi. C.E.
It was described that by ordinary process of manufac-
ture, the head, or end of the link, out of which the eye,
or hole for the connecting pin, was bored, had been
sometimes welded on to a parellel rolled bar, or, at other
times, been hammered to the required form; both these
methods were, however, objectionable, owing, iu the
former case, to the insecurity, and in the latter to the
tediousness and expense. By the method introduced by
Mr. Howard, the bars were rolled at once into the re-
quisite form; the shingle, or faggot, was first passed
longitudinally, at a welding heat, through grooved rol-
lers, in the ordinary manner, and then, before being
drawn down to the intended thickness, was carried to
rollers having bosses, or increased ctiatneters at the places
corresponding to the heads to be produced, and there
passed to and fro between the rollers transversely, or am ss
the breadth of the bar, thus receiving a pressure only
at the enlarged vans of the rollers, which gave the ne-
cessary increase of breadth at the heads; it was then
taken to plain finishing rollers, and drawn out lorgiiu-
dinally in the usual manner, until it atta'ned the
required length and thickness; the heads being after-
wards trimmed by machinery to the exact dimensions,
and the holes drilled for the pins.
It was stated that the chains of the large suspension
Fridge, erected by Mr. W. Tierney Clarke over the
Danube, at Pesth, which lately so satisfactorily with-
stood the heavy strain brought upon it by a retieati,g
army, were constructed on this system at the King and
Queen Iron Works at Rotherhithe; as were those for
lilting the tubular bridge at Conway, and over the Menai
Straits; and also that the links for a bridge now erecting
by M. Viguoles, at Kieff, in Russia, were manufactured
by another firm, under licence to use Mr. Howard's
system.

- Some interesting observations were recorded of the
results of the experiments for determining the strength
of these bars, showing them to possess great elasticity and
freedom from permanent set.
The discussion elicited some useful remarks as to
proportions of the area of the body and of the head,
and of the diam,ter of the pin, which, it was shown, had
much influence on the resisting power of the heads;
the larger the pin the less being the tendency to rupture
the eye.

The process appeared to be admitted as a great
improvement on the ordinary mode of manufacture, and
tending to give confidence to the Engineer that his
designs could be executed in metal, uninjured by mani-
pulation.
At the monthly ballot the following candidates were
duly elected:—

The Earl of Rlsse, President of the Royal Society,
&c., a 4 an honorary member. J. Samuel, A. Martin,
H. Robertson, and W. Radford, as membgrs. C. Cara-
mel!, R. NI. Marchant, and J. A. Joseph, as associates.
The following papers were announced to be read at the
meeting of Tuesday, June 12:—" On the construction
of a collar roof, with arched trusses of bent timber,
at East Horseley Park," by the Earl of Lovelace,
Assoc. inst. C.E., and " A description of the bridge
erected at Athlone." By Lieu'. Colonel H. D. Jones,
R E., M. Inst. C.E.