18J1.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



331 



and the Tomb of Francis the 1st are monuments perfect in the details 

 of their ornamental sculpture, in which they may contend with classic 

 antiquity, the Revival however was never a servile imitator of the 

 Greek and the Romans. This epoch is particularly remarkable for 

 tlie composition of capitals and arabesques. 



From the reign of Henry the 4th, the Revival begins to lose part of 

 its charm, ornaments became heavy, too numerous, and neglected in 

 their execution, showing how much art had declined. 



Under Louis the 13th and 14th, the direction given to ornamental 

 sculpture was in some degree stationary, but at the end of that age, 

 during the Regency and the whole reign of Louis 15th, the decline 

 was rapidly going on. In fact, the corruption of form was such that 

 no epoch in the history of the art has ever produced anything similar. 

 In the details of the architecture of this period, we witness the com- 

 plete absence of the observation of nature, which hitherto had always 

 been looked up to as a guide. 



Under Louis 16th, it was seen how little this capricious style was 

 adapted to the decoration of severe edifices, and a return to the an- 

 tique was begun by the architects Soufflot and Servandoni. There were 

 still to be seen however remains of the influence of that bad taste 

 which gave way to the revolution of 17S9, and the serious study of 

 the antique which has been pursued in the 19th century. 



THE ETCHING CLUB. 

 This association has been formed by twelve artists (eleven painters 

 and one sculptor), composed of the following gentlemen, whose names 

 will at once be recognized as amongst the most rising of the day; — 

 Redgrave, A.R.A; Webster, A.R.A.; Knight, A.R.A.; Cope, Taylor, 

 Creswick, Horsley, Townsend, Stonhouse, Bell, and F. Stone, with the 

 view of reviving the older excellence of the art of etching, and of 

 conferring upon the popular literature of the country, especially 

 poetry, a more pleasing, original, and arlist-like mode of illustration. 

 The first work that they have sent forth, consists of a series of eighty- 

 two illustrations of Goldsmith's exquisite poem, "The Deserted Vil- 

 lage. These illnstrations, in whatever way regarded, whether for 

 originality of conception, beauty of composition, truth and delicacy of 

 feeling, or correctness of delineation, are worthy of the highest praise. 

 We regret, however, to perceive that the club have adopted the bar- 

 barous practice of destroying tlie plates after taking a certain number 

 of impressions, which, in these days, is quite inexcusable. 



FOOT BRIDGE OVER THE RIVER WHITADDER. 



Sib — In the cumber of your Journal for July last, there is a descrip- 

 tion of a proposed new construction for railway viaducts on the tension 

 bar principle, in which the writei refers to the foot bridge over the 

 river Whitadder, in Berwickshire, on the property of George Turnbull, 

 E^q., of Abbey St. Bathans, as an instance in which the princi;ile 

 he proposes has been applied to bridges. The principle however as 

 adopted at Abbey St. Bathans foot bridge is not carried so far as 

 in the proposed railway viaduct, and as it is simple in its construction, 

 and is found to answer the purpose well, you may consider the accom- 

 panying sketch of its details not unworthy of a place in your Journal. 



In 1821 Mr. Robert Stevenson of Edinburgh,* designed a bridge for 

 the river Almond, in Edinburghshire, in which the principle of sup- 

 porting the roadway by iron bars passing underneath was first adopted. 

 This plan however differs from that now in use at Abbey St. Bathans' 

 bridge and elsewhere, as the chains for supporting the roadway are 

 fixed in the abutments, whereas at Abbey St. Bathans the roadway 

 beams themselves are made to resist the strain. Mr. Smith of Dean- 

 iton, has erected a foot bridge of this kind 103 feet span near Doune. 



I am not aware where and by whom the plan of fixing the tension 

 bars to the extremities of the roadway beams was first adopted, but 

 the principle has now come into pretty general use. A beam may in 

 this way be rendered perfectly rigid, and even forced into a slightly 

 arched form, and from the lightness and compactness of the whole it 

 possesses many advantages over the other methods in which the same 

 thing is accomplished. 



In 1S33 a bridge was erected on the tension bar principle over an 

 arm of the Lake of Geneva. It has 13 openings of 55 feet span, and 

 is 25 feet broad. The same plan has been adopted for two foot bridges 

 of 138 and 81 feet span respectively erected several years since over 

 the river Ness, near Inverness, and also for a bridge over the river 

 Whitadder, in Berwickshire, at Hutton Mill, designed by Mr. Jardine, 

 of Edinburgh, which consists of three openings 60 feet span. Mr. 



* See Edinburgh Philosophical Journal for October, 1821, and Drewry on 

 Suspension Briilges, page 30. 



Smith has also applied tension rods very successfully for supporting 

 the floors of the Deanston cotton works, where they have been in use 

 for many years. These, so far as I am aware, are the only instances 

 in which this principle has been adopted. 



The Whitadder is subject to heavy floods, especially in the winter 

 season, which interrupts the intercourse between the opposite banks, 

 and as there is no bridge within many miles of Abbey St. Bathans, the 

 want of some means of communication was long felt to be a great in- 

 convenience, and several attempts had been made to build a foot 

 bridge by which the water might be crossed at all times, without hav- 

 ing recourse to the inconvenient and often dangerous alternatives of a 

 ferry-boat or a ford: but the heavy floods and ice during the winter 

 destroyed the erections by carrying away the piers. 



Messrs. R. Stevenson and Sons, of Edinburgh, being applied to for 

 a design of a bridge, recommended one on the tension bar principle, 

 from its simplicity of construction and the moderate cost at which it 

 might be executed. 



'rhe bridge was commenced at the beginning of last summer, and 

 finished in the course of six months. Its total length is IGO feef, and 

 its breadth 4 feet. The planking is 16 feet above the water, which 

 rises 11 feet on the piers during floods, and although the bridge was 

 originally intended for foot passengers only,liorses have been occasionally 

 taken across it. It consists, as will be seen from the sketch fig. 1, of 

 two main openings of CO feet span, and a smaller one of 24 feet span. 

 The beams are supported upon piers of coursed Graywacke rubble. 

 The two in the centre measure 10 feet x 7 feet at the base, and batter 

 to G ft. 6 in. X 4 feet at the top. The one which is most exposed to 

 the water is founded upon rock, at the depth of 4 feet under the bed 

 of the river, and the other is founded upon a platform of timber laid 

 on gravel. A causeway of river stones is laid round the base of the 

 piers to protect their foundations from the run of the water. The 

 beams for supporting the roadway planking were made of four pieces 

 of timber for the convenience of getting them readily conveyed across 

 the hills; they measure 11 inches X 6 inches, and are formed of planks 

 of red pine 11 inches x 3 inches. Two of them are 37 feet long, and 

 two 27 feet, so that when put together the scarphs which are 2 ft. G 

 in. long occur at dift'erent places and exactly over the uprights. The 

 planks are firmly fixed together by means of oaken treenails 3 feet 

 apart, driven right through and wedged at both ends. The ends of 

 the main beams fit into cast iron shoes, as shown in figs. 5 and 0, and 

 the tension rods which go under the beams, and support them by means 

 of the uprights, pass through auger holes in the centre of the beams, 

 and are secured by means of screw nuts G inches long to the back part 

 of the iron shoes, as shown in figs. 5 and G. The diameter of the ten- 

 sion rods is one inch. The screws are used in order to tighten up the 

 rods, which is done until the beams are quite rigid. 



Figs. 5 St C— .Section and side view of tlie Ends of ihe Beams. 



The main beams and iron work of the bridge were made by Messrs. 

 J. B. Maxton and Co., of Leith Engine-works, and were proved in the 

 work-yard with a weight of one and a half ton, before being sent to 

 their destination. The remainder of the wood work was executed by 

 Mr. Thomas Swan, of Cranshaw. 



The entire cost of the bridge was as follows: 



Masonwork - - -£10 175 



Main beams and iron work - - 50 



Planking and railing - - 78 G 



Forming approaches, &c. - - 8 5 



I remain, your obedient servant, 



47, Melville Slreel, Edinburgh, 

 27M August, 1841. 



£237 18 5 

 John R. Wilson. 



2X2 



