116  DrvorGILLA BALIOL AND OLD BRIDGE OF DUMFRIES. 
sion of danger was always present to the mind of the traveller ; 
and it was customary to erect crosses at the fords, where 
prayers might be offered for safety before attempting the passage 
of the waters. One such cross remains in Dumfriesshire, 
although possibly not exactly in its original position. It stands 
at the old ford of the Nith, near the village of Thornhill. 
As civilisation advanced and population and travelling in- 
creased, the building of bridges became a matter of urgency, 
and gradually led to their ercetion along the principal routes 
throughout the country ; and so great were the advantages accru- 
ing in course of time felt to be, as to lead benevolent and 
pious persons, in those early days, to bequeath large sums of 
money for the purpose of building and maintaining bridges. 
The Church regarded bridge-building as pious work, and 
Churchmen were active promoters of the movement, and fre- 
quently themselves the architects of the structures. 
The first known bridges in Britain cross the streams at 
Dartmoor. They exhibit peculiar construction; the piers are 
built of granite blocks, and the spaces between them are spanned 
with great slabs of similar material, some of them fifteen feet in 
length and six in breadth, which form the roadway. One of 
these bridges measures thirty-seven feet in length. It is said 
cyclopean bridges such as these exist nowhere else; not even in 
Brittany, noted for aboriginal monuments, and probably they are 
‘cceval with the building of Stonehenge. 
The Romans were noted experts in the art, who built in 
England bridges both of wood and stone, and fragments of the 
latter yet exist. 
The curious triangular bridge at Croyland is referred to, it 
is said, in an ancient charter of the year 943. The architecture 
of the existing structure, however, clearly proves it to belong to 
the thirteenth century. 
The first medizeval bridges of which authentic accounts are 
preserved are a pair erected over the two branches of the river 
Lea at Stratford, built between 1100 and 1118 by Matilda, 
Queen-Consort of Henry I., who narrowly escaped drowning 
there, and where many others had perished; she bequeathed 
certain manors and a mill to the Abbess of Barking for their 
maintenance and repair. 
London Bridge, although by no means the longest in Eng- 
