ionaries. He began the work at once by forming an
embankment twenty feet high, which he carried some distance across the
treacherous soil, when the whole affair sank down one day and
disappeared! Undismayed, Stephenson began again, and went on steadily
depositing thousands on thousands of tons of earth, which were greedily
swallowed up, until at last a solid foundation was obtained over the
greater part of the bog. But there was a particularly soft part of it,
known by the name of the "flow moss," which was insatiable. Over this
hurdles interwoven with heath were spread, and on these earth and gravel
were laid down. When this road showed a tendency to sink below the
level, Stephenson loaded the moss beyond the track to balance it; when
water oozed through, he invented a new kind of drain-pipe formed of old
tallow casks, headed into each other, and ballasted to keep them down,
and at last the feat was accomplished--the railway was run over the wet
quaking moss on firm dry land.

It was in the formation of this, the true beginning of railways, that
the British "navvy" was called into being. To perform the laborious
work, Stephenson employed the men called "inland navigators," in other
words, the canal excavators. This body of strong "navigators" or
"navvies" formed the nucleus, which gathered recruits from all parts of
the kingdom. As the work of railway making, which thenceforward grew
fast and furious, was unusually severe, only men who were unusually
powerful were suited for the navvy ranks, so that they became a distinct
class of gigantic men, whose capacity for bread and beef was in
accordance with their muscular development and power to toil. Splendid
fellows they were, and are; somewhat rugged and untamed, no doubt, with
a tendency to fight occasionally, and a great deal of genuine kindness
and simplicity. That they are capable of being imbued with refined
feeling, noble sentiment, and love to God, has been shown by the
publications of Miss Marsh, which detail that lady's interesting and
earnest labours to bring the unbelievers among these men to our Saviour.

Another celebrated piece of railway engineering is the _Britannia
Bridge_ over the Menai Straits, which separates Caernarvonshire from the
island of Anglesey. This was the first bridge ever built on the tubular
principle. The importance of crossing the strait was very great, as it
lay in the direct route to Holyhead and Ireland. Telford, the engi