In conclusion, I must observe that no man can be more sensible than I am of the great advantage it would be to me as a civil engineer to be better acquainted with geology, as well as with many other branches of science, that I have endeavoured to inform myself on the subject, and that I have not altogether thrown away the many opportunities afforded me in my professional pursuits; but that if from a conviction that you possessed information far more extensive than mine, if from doubts of the sufficiency of my abilities or the means I was likely to bring to bear upon the subject, if from a fear of such consequences as you now anticipate, you had kindly, on any one of the many occasions when I have had the pleasure of meeting you, intimated that you had any suggestions to make to me, I should have been anxious to have availed myself of your assistance. But after the lapse of years, the first intimation I have of such doubts is the very public expression of a very strong opinion, which, if weight be attached to it, must tend to alarm the public unnecessarily, and to injure the value of the property of individuals who have embarked several millions in that property.
Between Chippenham and Bristol the nature of the building stone enabled Mr. Brunel, at moderate cost, to make the bridges, tunnel fronts, and stations ornamental features in the picturesque scenery through which the railway passes.
He took great pleasure in finishing minutely the various designs, and making them correct in their proportions and details. One tunnel front, near Bristol, may be singled out for especial mention. During its construction a part of the ground behind slipped away, and it became unnecessary to complete the top of one of the side walls. It was therefore left unfinished, and was planted with ivy so as to present the appearance of a ruined gateway.
The roofs of the Bath and Bristol stations are of large span, and are handsome architectural structures. They are each in the form of a Tudor arch; the Bristol roof is 72 feet span, and the Bath roof 50 feet span. The framing is an example of a peculiar form of construction, somewhat analogous to that adopted in the large shipbuilding sheds in the dockyards. There are no cross tie-rods, but each principal of the roof is formed of two frameworks, like cranes, meeting in the middle of the roof; the weight being carried on columns near the edge of the platform, and the tail ends of the frames held down by the side walls. As the two frames do not press against each other at their meeting point at the ridge of the roof, there is no outward thrust. The side walls being on a viaduct could not without difficulty have been made to resist a horizontal thrust.
At the Bristol station Mr. Brunel introduced hydraulic machinery for working lifts. By these the waggons were lowered to and raised up from the goods shed, which was placed at the level of the ground, about 12 feet below the railway.
Although the works already described were completed in 1841, the permanent terminus at Paddington was not commenced till the year 1849. It was completed in 1854. Previously to that time a temporary station had been used, the booking offices being under the arches of the Bishop’s Road bridge.
As the level of the railway was lower than that of the surrounding land, no exterior architectural effect could be produced; but Mr. Brunel took this opportunity to carry out his views as to the proper structural use of metal in works of this description.
In the design of the ornamental details, he obtained the assistance of Mr. (now Sir Matthew) Digby Wyatt.
The interior of the principal part of the station is 700 feet long and 238 feet wide, divided in its width by two rows of columns into three spans of 68, 102, and 68 feet, and is crossed at two points by transepts 50 feet wide, which give space for large traversing frames. The roof is very light, consisting of wrought-iron arched ribs, covered partly with corrugated iron and partly with the Paxton glass roofing, which Mr. Brunel here adopted to a considerable extent. The columns which carry the roof are very strongly bolted down to large masses of concrete, to enable them to resist sideways pressure.
This station may be considered to hold its own in comparison with the gigantic structures which have since been built, as well as with older stations. The appearance of size it presents is due far more to the proportions of the design than to actual largeness of dimension. The spans of the roof give a very convenient subdivision for a large terminal station, dispensing with numerous supporting columns and at the same time avoiding heavy and expensive trusses. The graceful forms of the Paddington station, the absence of incongruous ornament and useless buildings, may be appealed to as a striking instance of Mr. Brunel’s taste in architecture and of his practice of combining beauty of design with economy of construction.