The Sun.
London, England, 1844-05-10 00:00:00

THE SUN, LONDON, FRIDAY EVENING, MAY 10, 1844.

INSTITUTION OF CIVIL
ENGINEERS.

Afiky 7.—The second part of Mr. Fairbairn's paper,
which remained unfinished from the last meeting, was
read. It noticed the remarkable richness and purity of
tip iron ores of.the East, And-the superior quality of the
Damascus steel, produced from iron made apparently in
the rudest and most primitivomanuer : it was remark-
able that, up to the present time, there had been but
little change in the mannerofmanufacturing charcoal iron,
even in England ; this might be accounted for by the
suriall quantity of wood charcoal used for smelting iron ;
but* appeared that, with The exception of that which was
sent into Staffordshire and South Wales for mingling
with the lean ores of the coal measures, but little of the
hmmatite, or rich ores of Lancashire, Cumberland, Corn-
wall, or Devonshire, was used, although in richness and
quality of metal they equalled those of foreign countries.
The paper then entered at length upon the experiments
on the transverse strength of the Turkish iron, and also
of the iron from other rich ores, presenting the results in
tabular form, mingled with those which had been reported
on previous occasions, in the Transactions of the Philoso-
phical Society of Manchester, and the reports of the
British Association. These tables were arranged so as to
afford the means of comparison of the strength and other
qualities of various irons, and also for practical purposes,
to furnish a guide for selecting such irons, as, by proper
mixtures of the different kinds, should enable unerring
results to be arrived at by the founder when engaged in
producing castings for the engineer, the architect, or for
various purposes in the arts, or in construction. Simple
rules were also given for finding the breaking weight of
beams cast from the fifty-two kinds of iron which had
been experimented upon. The importance of the sub-
ject-of the paper, the novelty of the application of Mr.
Clay's system, and the unweared attention of Mr. Fair-
bairn, together with Mr. Hodgkinson, in the numerous
experiments they had made, were fully appreciated by
the meeting, and it was announced that the valuable
tables would speedily be published entire in the minutes
of proceedings of the institution. A specimen of steel
made from the Turkish ore, and a knife manufactured
from it by Mr. Durham, of Regent-street, were exhibited,
and were much admired. A letter was read from Dr.
Schafhaeuth, drawing attention- to some experiments
made by Sir D. Brewster on the prismatic colours gene-
rated in homogeneous bodies when pressure was applied
to them ; these experiments were recorded in the
Philosophcal Transactions for 1816. They furnished
a method of rendering visible and of measuring the
mechanical changes which took place during the com-
pression, dilatation, or bending of transparent bodies.
He also stated that the tints produced by polarized
light were' correct measures of the compressing and
dilating forces, and, by employing transparent gums of
[ different elasticities, the changes which occurred in
bodies before they were either broken or crushed could
be ascertained, and that forming models of arches of
simple refracting substances, such as gum copal, &c.,
, giving difft.rent degrees of roughness to the touching
surfaces of the voussoirs, and exposing the model to
polarized light, the results of any degree of friction on
the joints would be readily observed. It was Stated that
similar experiments had been tried by Mr. Bist
at Paris, almost simultaneously with Dr. Brewster,
and that without doubt they had materially assisted
Dr. Robison in his valuable treatise on the strength
of materials. A description of the iron dock-gates at
Montrose harbour, by Mr. James Leslie, M. Inst,
of Civil Engineers, was then read. These gates were
described in great detail, giving all the dimensions
of the several parts, which were fully shown by some
elaborate drawings. The framing was of cast iron,
covered on both sides with wrought-iron plates, 3-Bths
of an inch and 5-16ths of an inch thick, riveted on so as
to be water-tight, and to render the gates buoyant, and
partly to compensate' for the weight of metal in them,
which was about 87 tons. The gates were 55 feet wide
and 22 feet 6 inches deep, and were entirely composed of
iron, except the bottom bars and the false mitres, which
were of oak. The sluice valves were of iron, without
any brass on the faces, but their backs were covered
with zinc plates, and the bolts had zinc nuts screwed over
the Iron ones, in order to check the oxydation of the
iron by the galvanic action of the two metals. A general
account of Montrose harbour was given ; and it appeared
that although there bad existed some doubt as to the
successful formation of a harbour in such bad ground,
being entirely sand and gravel, which stood full of water
to within a few feet of the surface, the 'work having been
submitted to Mr. Walker, President of the Institution,
and having his approval, had been satisfactorily exe-
cuted, and stood well. A model of the large swinging
gib crane used by the contractors at Granton Pier,
Edinburgh, and a drawing of the mode of raising the
standpipe at the East London Waterworks, by Mr. Wick-
steed, were exhibited.