68 | Mr. Ware’s Design for 
to obtain subscribers to such a project, but not to effect a dry and 
secure passage for men and carriages under the Thames. 
The method of Semiramis was simple in design and certain of 
success. Troughs holding water, such as the canal aqueducts 
over rivers, are to be seen in all parts of the country; and there 
can be no doubt, that such an arch-way as that before described * 
in the estimate commencing this statement, executed in the open 
air, and uninterrupted by water during such erection, by means of 
cofferdams, would have a successful issue, and be perfectly dry 
under a river, for a thoroughfare for passengers and carriages. 
In modern times, a cheaper way of rendering the bed of a river dry 
has been discovered than that of Semiramis, which was by means 
of a reservoir to receive the waters of it, or even than that of Trajan, 
in building the bridge across the Danube, which was by making a 
temporary new channel to receive its stream. We have lately seen 
the piers of Waterloo Bridge and of Southwark Bridge laid dry, in 
the bed of the Thames, by means of cofferdams, the use of which, 
in keeping the space enclosed in them free from water, has been 
greatly extended by the facility obtained by means of steam- 
engines; and by similar means may an arch-way be constructed 
of almost any useful dimensions under the river, and with the 
same success, and not with more interruption to the navigation of 
the Thames than would be caused by one of the vessels in the pool 
getting athwart the stream, and remaining so for a few months. 
Since the foregoing statement was made, an advertisement has 
appeared of the intention of applying to Parliament for leave to 
bring in a bill to erect a patent wrought-iron bar bridge of sus- 
pension, from some part of the parish of St. Botolph, Aldgate, 
over the Thames, to some part of St. Mary, Bermondsey, of such 
* The following account of the suspended gardens of Nebuchadnezzar, at 
Babylon, extracted from Diodorus, will show the care used by him, to render 
the rooms under them dry. ‘ On the walls were laid stones, 16 feet long and 
4 feet broad ; these were covered with reeds coated with brimstone, on which 
were laid double tiles, cemented together, and on them were laid sheets of 
lead.”, 
