occupied the evening at his inn in composing some stanzas, entitled An Address to the River Avon.' And when on his way back to Shrewsbury, while resting for the night at Bridgenorth, he amused himself with revising and copying out the verses for the perusal of Andrew Little. "There are worse employments," he said, "when one has an hour to spare from business;" and he asked his friend's opinion of the composition. It seems to have been no more favourable than the verses deserved; for, in his next letter, Telford says, "I think your observations respecting the verses to the Avon are correct. It is but seldom I have time to versify; but it is to me something like what a fiddle is to others. I apply to it in order to relieve my mind, after being much fatigued with close attention to business."

It is very pleasant to see the engineer relaxing himself in this way, and submitting cheerfully to unfavourable criticism, which is so trying to even the best of tempers. The time, however, thus taken from his regular work was not loss, but gain. Taking the character of his occupation into account, it was probably the best kind of relaxation he could have indulged in. With his head full of bridges and viaducts, he thus kept his heart open to the influences of beauty in life and nature; and, at all events, the writing of verses, indifferent though they might have been, proved of this value to himthat it cultivated in him the art of writing better prose.

CHAPTER VII.

IRON AND OTHER BRIDGES.

SHREWSBURY being situated in the immediate neighbourhood of the Black Country, of which coal and iron are the principal products, Telford's attention was naturally directed, at a very early period, to the employment of cast iron in bridge-building. The strength as well as lightness of a bridge of this material, compared with one of stone and lime, is of great moment where headway is of importance, or the difficulties of defective foundations have to be encountered. The metal can be moulded in such precise forms and so accurately fitted together as to give to the arching the greatest possible rigidity; whilst it defies the destructive influences of time and atmospherie corrosion with nearly as much certainty as stone itself.

The Italians and French, who took the lead in engineering down almost to the end of last century, early detected the value of this material, and made several attempts to introduce it in bridge-building; but their efforts proved unsuccessful, chiefly because of the inability of the early founders to cast large masses of iron, and also because the metal was then more expensive than either stone or timber. The first actual attempt to build a cast iron bridge was made at Lyons in 1755, and it proceeded so far that one of the arches was put together in the builder's yard; but the project was abandoned as too costly, and timber was eventually used.

It was reserved for English manufacturers to triumph

over the difficulties which had baffled the foreigners. Shortly after the above ineffectual attempt had been made, the construction of an iron bridge over the Severn near Broseley formed the subject of discussion among the iron-masters. It was proposed to substitute a bridge in place of the ferry which then connected the two banks of the river; and Mr. John Wilkinson, who had, as some thought, an extravagant, but, as results have proved, a truly prophetic, appreciation of the extensive uses to which iron might be applied, strongly urged that the structure should be of that material. Everybody knew of Mr. Wilkinson's hobby, and of his prognostication that the time would come when we should live in houses of iron, and even navigate the seas in ships of iron. When he insisted upon an iron bridge being built at Coalbrookdale, people said he was "iron-mad." But as he was a powerful man in his day" the great iron-master" he was calledhis suggestion could not be dismissed without consideration; and the Bridge Company, which had been formed, determined to take the opinion of Mr. Pritchard, of Shrewsbury, on the subject. That architect's opinion was favourable to the suggestion of the iron-master ; and he was requested to supply a design of an iron bridge, which was eventually adopted. The work was erected, under contract, by Messrs. Reynolds and Darby, iron-masters at Coalbrookdale, in the year 1777. The bridge has only one semicircular arch of 100 feet span, each of the great ribs consisting of two pieces only. Though it was on the whole a bold design, and well executed, the error was committed of treating the arch as one of equilibrium. There also seems to have been some defect in the abutments, which were forced inwards by the pressure of the earth behind them, and the iron arch was thus partially fractured and raised in the middle. Nevertheless, the first cast iron bridge

ever erected proved a very serviceable structure, and it remains so to this day.

It is a curious circumstance that the next contriver of an iron bridge was no other than the same Tom Paine whose political writings Telford had so much admired. While residing in America, Paine had proposed to build a bridge of this material 400 feet in span over the Schuylkill, and he came to England to take out a patent for his invention,' and to order a bridge after his plan, the materials of which were manufactured at the Rotherham Iron-works. They were delivered in London, and fitted together on a bowling-green at Paddington. But the French Revolution breaking out, Paine hastened to

Paris to join the "Friends of Man," leaving his bridge in the hands of his creditors. His democratic associates having incarcerated him in the Luxembourg prison, he lay there for eleven months, but finally escaped to America. In the mean time the materials had been purchased for erection over the river Wear, at Sunderland, where the second iron bridge in England was erected, after a design by Mr. T. Wilson, in the year 1796. Mr. Robert Stephenson has characterised this bridge as "a structure which, as regards its proportions and the small quantity of material employed in its construction, will probably remain unrivalled." 1 Indeed, it was long regarded as the greatest triumph of the art.

Its span