an iron girder bridge in such a position. Mr. Brunel's father, when he
constructed the Thames Tunnel, lined it with brickwork foot by foot as
he went on, and that lining sustained the heavy weight of the bed of the
river and the river itself.

If you leave London by either of the southern lines, all of which are at
a high level, you go for miles on viaducts consisting of brick arches
carried on brick walls. If you leave by the northern lines, you plunge
into tunnel after tunnel lined with brickwork, and kept secure by such
lining. Mile after mile of London streets, and those in the suburbs,
present to the eye little but brick buildings; dwelling houses, shops,
warehouses, succeed one another, all in brickwork, and even when the eye
seems to catch a change, it is more apparent than real.

The white mansions of Tyburnia, Belgravia, South Kensington, and the
neat villas of the suburbs are only brickwork, with a thin coat of
stucco, which serves the purpose of concealing the real structure--often
only too much in need of concealment--with a material supposed to be a
little more sightly, and certainly capable of keeping the weather out
rather more effectually than common brickwork would.

More than this, such fine structures, apparently built entirely of
stone, as are being put up for commercial purposes in the streets of the
city, and for public purposes throughout London, are all of them nothing
more than brick fabrics with a facing of masonry. Examine one of them in
progress, and you will find the foundations and vaults of brickwork, and
not only the interior walls, but the main part of the front wall,
executed in brickwork, and the stone only skin deep. There are, however,
two or three ways of making use of brickwork without covering it up, and
of gaining good architectural effects thereby, and to these I beg now to