repeat his tubular
bridges both in Lower Canada and in Egypt. The success of the tubular
system, as adopted at Menai and Conway, was such as to recommend it for
adoption wherever great span was required; and the peculiar circumstances
connected with the navigation of the St. Lawrence and the Nile, may be
said to have compelled its adoption in carrying railways across those
great rivers.

The Victoria Bridge, of which Robert Stephenson was the designer and
chief engineer, is, without exception, the greatest work of the kind in
the world. For gigantic proportions and vast length and strength there
is nothing to compare with it in ancient or modern times. The entire
bridge, with its approaches, is only about sixty yards short of _two
miles_, being five times longer than the Britannia across the Menai
Straits, seven and a half times longer than Waterloo Bridge, and more
than ten times longer than the new Chelsea Bridge across the Thames! It
has not less than twenty-four spans of 242 feet each, and one great
central span--itself an immense bridge--of 330 feet. The road is carried
within iron tubes 60 feet above the level of the St. Lawrence, which runs
beneath at a speed of about ten miles an hour, and in winter brings down
the ice of two thousand square miles of lakes and rivers, with their
numerous tributaries. The weight of iron in the tubes is about ten
thousand tons, supported on massive piers, which contain, some six, and
others ten thousand tons of solid masonry.

So gigantic a work, involving so heavy an expenditure--about 1,300,000
pounds--was not projected without sufficient cause. The Grand Trunk
Railway of Canada, upwards of 1200 miles in length, traverses British
North America from the shores of the Atlantic to the rich prairie country
of the Far West. It opens up a vast extent of fertile territory for
future immigration, and provides a ready means for transporting the
varied products of the Western States to the seaboard. So long as the
St. Lawrence was relied upon, the inhabitants along the Great Valley were
precluded from communication with each other for nearly six months of the
year, during which the navigation was closed by the ice.

The Grand Trunk Railway was designed to furnish a line of communication
through this great district at all seasons; following the course of the
St. Lawrence along its north bank, and uniting the principal towns of
Canada. But stopping short on the north shore, it