[Footnote 1: Address of Sir Frederick Joseph Bramwell, F.R.S., on
his election as president of the Institution of Civil Engineers.
January 13, 1885.]
By Sir F. J. BRAMWELL.
I propose to devote the very limited time at my disposal to the
consideration of some of the most important of those improvements
which are obviously and immediately connected with civil engineering.
I am aware of the danger there is of making a serious mistake, when
one excludes any matter which at the moment appears to be of but a
trivial character. For who knows how speedily some development may
show that the judgment which had guided the selection was entirely
erroneous, and that that which had been passed over was in truth the
germ of a great improvement? Nevertheless, in the interests of time
some risk must be run, and a selection must be made; I propose,
therefore, to ask your attention while I consider certain of
(following the full title of Division I.) "The apparatus, appliances,
processes, and products invented or brought into use since 1862."
In those matters which may be said to involve the principles of
engineering construction, there must of necessity be but little
progress to note.
Principles are generally very soon determined, and progress ensues,
not by additions to the principles, but by improvement in the methods
of giving to those principles a practical shape, or by combining in
one structure principles of construction which had been hitherto
used apart. Therefore, to avoid the necessity of having a pause, in
referring to a work, by finding that one is overstepping the boundary
of principle, and trenching within the domain of construction, I think
it will be well to treat these two heads together.
If my record had gone back to just before 1851 (the date of the great
exhibition), I might have described much progress in the principles
of girder construction; for shortly prior to that date, the plain
cast-iron beam, with the greater part of the metal in the web, and
with but little in the top and bottom flange, was in common use; and
even in the preparation of the building for that exhibition, it is
recorded that one of the engineers connected therewith had great
difficulty in understanding how it was that the form of open work
girder, with double diagonals introduced therein (a form which was for
years afterward known as the exhibition girder), was any stronger
than a girder with open panels separated by uprights, and without any
diagonals. But, long before 1862, the Warren and other truss-girders
had come into use, and I am inclined to say that, so far as novelty
in the principle of girder-construction is concerned, I must confine
myself to that combination of principles which is represented by the
suspended cantilever, of which the Forth Bridge, only now in course
of construction, affords the most notable instance. It is difficult to
see how a rigid bridge, with 1,700 foot spans, and with the necessity
for so much clear headway below, could have been constructed without
the application of this principle.