across the Straits had
not yet been contemplated.

The Dublin Chamber of Commerce passed resolutions in favour of
Stephenson's line, after hearing his explanation of its essential
features. The project, after undergoing much discussion, was at length
embodied in an Act passed in 1844; and the work was brought to a
successful completion by his son, with several important modifications,
including the grand original feature of the tubular bridges across the
Menai Straits and the estuary of the Conway. Excepting these great
works, the construction of this line presented no unusual features;
though the remarkable terrace cut for the accommodation of the railway
under the steep slope of Penmaen Mawr is worthy of a passing notice.

About midway between Conway and Bangor, Penmaen Mawr forms a bold and
almost precipitous headland, at the base of which, in rough weather, the
ocean dashes with great fury. There was not space enough between the
mountain and the strand for the passage of the railway; hence in some
places the rock had to be blasted to form a terrace, and in others
sea-walls had to be built up to the proper level, on which to form an
embankment of sufficient width to enable the road to be laid. [Picture:
Penmaen Mawr. (By Percival Skelton.)] A tunnel 10.5 chains in length was
cut through the headland itself; and on its east and west sides the line
was formed by a terrace cut out of the cliff, and by embankments
protected by sea walls; the terrace being three times interrupted by
embankments in its course of about 1.25 mile. The road lies so close
under the steep mountain face, that it was even found necessary at
certain places to protect it against possible accidents from falling
stones, by means of a covered way. The terrace on the east side of the
headland was, however, in some measure protected against the roll of the
sea by the mass of stone run out from the tunnel, and forming a deep
shingle bank in front of the wall.

The part of the work which lies on the westward of the headland
penetrated by the tunnel, was exposed to the full force of the sea; and
the formation of the road at that point was attended with great
difficulty. While the sea wall was still in progress, its strength was
severely tried by a strong north-westerly gale, which blew in October,
1846, with a spring tide of 17 feet. On the following morning it was
found that a large portion of the rubble was irreparably injured, and 200
yards