10th March, 1793
*[2] Referring to the burning of Dr. Priestley's library.

*[3] The preparation of some translations from Buchanan which he
had contemplated.

*[4] Letter to Mr. Andrew Little, Langholm, dated Shrewsbury,
29th September, 1793.

*[5] John Wilkinson and his brother William were the first of the
great class of ironmasters. They possessed iron forges at Bersham

near Chester, at Bradley, Brimbo, Merthyr Tydvil, and other places;
and became by far the largest iron manufacturers of their day.

For notice of them see 'Lives of Boulton and Watt,' p. 212.
*[6] Letter to Mr. Andrew Little, Langholm, dated Shrewsbury,

3rd November, 1793.
CHAPTER VI.

THE ELLESMERE CANAL.
The ellesmere canal consists of a series of navigations proceeding

from the river Dee in the vale of Llangollen. One branch passes
northward, near the towns of Ellesmere, Whitchurch, Nantwich, and

the city of Chester, to Ellesmere Port on the Mersey; another,
in a south-easterly direction, through the middle of Shropshire

towards Shrewsbury on the Severn; and a third, in a south-westerly
direction, by the town of Oswestry, to the Montgomeryshire Canal

near Llanymynech; its whole extent, including the Chester Canal,
incorporated with it, being about 112 miles.

[Image] Map of Ellesmere Canal
The success of the Duke of Bridgewater's Canal had awakened the

attention of the landowners throughout England, but more especially
in the districts immediately adjacent to the scene of the Duke's

operations, as they saw with their own eyes the extraordinary
benefits which had followed the opening up of the navigations.

The resistance of the landed gentry, which many of these schemes had
originally to encounter, had now completely given way, and, instead

of opposing canals, they were everywhere found anxious for their
construction" target="_blank" title="n.建设；修建；结构">construction. The navigations brought lime, coal, manure, and

merchandise, almost to the farmers' doors, and provided them at the
same time with ready means of conveyance for their produce to good

markets. Farms in remote situations were thus placed more on an
equality with those in the neighbourhood of large towns; rents rose

in consequence, and the owners of land everywhere became the
advocates and projectors of canals.

The dividends paid by the first companies were very high, and it
was well known that the Duke's property was bringing him in immense

wealth. There was, therefore, no difficulty in getting the shares
in new projects readily subscribed for: indeed Mr. Telford relates

that at the first meeting of the Ellesmere projectors, so eager
were the public, that four times the estimated expense was

subscribed without hesitation. Yet this navigation passed through
a difficult country, necessarily involving very costly works; and

as the district was but thinly inhabited, it did not present a very
inviting prospect of dividends.*[1] But the mania had fairly set

in, and it was determined that the canal should be made. And
whether the investment repaid the immediate proprietors or not, it

unquestionably proved of immenseadvantage to the population of the
districts through which it passed, and contributed to enhance the

value of most of the adjoining property.
The Act authorising the construction" target="_blank" title="n.建设；修建；结构">construction of the canal was obtained in

1793, and Telford commenced operations very shortly after his
appointment in October of the same year. His first business was to

go carefully over the whole of the proposed line, and make a careful
workingsurvey, settling the levels of the different lengths,

and the position of the locks, embankments, cuttings, and aqueducts.
In all matters of masonry work he felt himself master of the

necessary details; but having had comparatively small experience of
earthwork, and none of canal-making, he determined to take the

advice of Mr. William Jessop on that part of the subject; and he
cordially acknowledges the obligations he was under to that eminent

engineer for the kind assistance which he received from him on many
occasions.

The heaviest and most important part of the undertaking was in
carrying the canal through the rugged country between the rivers

Dee and Ceriog, in the vale of Llangollen. From Nantwich to
Whitchurch the distance is 16 miles, and the rise 132 feet,

involving nineteen locks; and from thence to Ellesmere, Chirk,
Pont-Cysylltau, and the river Dee, 1 3/4 mile above Llangollen, the

distance is 38 1/4 miles, and the rise 13 feet, involving only two
locks. The latter part of the undertaking presented the greatest

difficulties; as, in order to avoid the expense of constructing
numerous locks, which would also involve serious delay and heavy

expense in working the navigation, it became necessary to contrive
means for carrying the canal on the same level from one side of the

respective valleys of the Dee and the Ceriog to the other; and
hence the magnificent aqueducts of Chirk and Pont-Cysylltau,

characterised by Phillips as "among the boldest efforts of human
invention in modem times."*[2] The Chirk Aqueduct carries the canal

across the valley of the Ceriog, between Chirk Castle and the
village of that name. At this point the valley is above 700 feet

wide; the banks are steep, with a flat alluvial meadow between
them, through which the river flows. The country is finely

wooded. Chirk Castle stands on an eminence on its western side,
with the Welsh mountains and Glen Ceriog as a background; the whole

composing a landscape of great beauty, in the centre of which
Telford's aqueduct forms a highly picturesque object.

[Image] Chirk Aqueduct
The aqueduct consists of ten arches of 40 feet span each.

The level of the water in the canal is 65 feet above the meadow,
and 70 feet above the level of the river Ceriog. The proportions

of this work far exceeded everything of the kind that had up to
that time been attempted in England. It was a very costly structure;

but Telford, like Brindley, thought it better to incur a considerable
capital outlay in maintaining the uniform level of the canal, than

to raise and lower it up and down the sides of the valley by locks
at a heavy expense in works, and a still greater cost in time and

water. The aqueduct is a splendid specimen of the finest class of
masonry, and Telford showed himself a master of his profession by

the manner in which he carried out the whole details of the
undertaking. The piers were carried up solid to a certain height,

above which they were built hollow, with cross walls. The spandrels
also, above the springing of the arches, were constructed with

longitudinal walls, and left hollow.*[3] The first stone was laid
on the 17th of June, 1796, and the work was completed in the year

1801; the whole remaining in a perfect state to this day.
The other great aqueduct on the Ellesmere Canal, named Pont-Cysylltau,

is of even greater dimensions, and a far more striking object in
the landscape. Sir Walter Scott spoke of it to Southey as "the

most impressive work of art he had ever seen." It is situated about
four miles to the north of Chirk, at the crossing of the Dee, in

the romantic vale of Llangollen. The north bank of the river is
very abrupt; but on the south side the acclivity is more gradual.

The lowest part of the valley in which the river runs is 127 feet
beneath the water-level of the canal; and it became a question with

the engineer whether the valley was to be crossed, as originally
intended, by locking down one side and up the other--which would

have involved seven or eight locks on each side--or by carrying it
directly across by means of an aqueduct.

The execution of the proposed locks would have been very costly,
and the working of them in carrying on the navigation would

necessarily have involved a great waste of water, which was a
serious objection, inasmuch as the supply was estimated to be no

more than sufficient to provide for the unavoidable lockage and
leakage of the summit level. Hence Telford was strongly in favour

of an aqueduct; but, as we have already seen in the case of that at