XIII. MODELS, ETC. 553 



The clear span of station roof is U40 feet ; the distance between side walls, 

 245 ft. 6 inches ; area of ground covered by the roof, 169,400 square feet; 

 number of columns in basement supporting the flooring, 720. 



The contractors for the iron work of the station and its erection were the 

 Butterly Iron Company, Staffordshire. 



The station was opened in the beginning of 1869. 



2O93d. Detail Drawing of Iron Lattice Girder Rail- 

 way Bridges on the Pacasmayo, Guadalupe, and Magdalena 

 Railway, 1872. Scales, 1 inch to 1 foot, and 3 inches to 1 foot. 



William Willis. 



The drawing represents reproductions of the original by Willis' aniline 

 process, executed by Vincent Brooks and Co. 



2098. Model of Bowstring Bridge, thrown over the canal at 

 Wormwood Scrubs, the tunnel of the Great Western Railway 

 passing under the canal. Council of King's College, London. 



22I6a. Model of a portion of the Pontcysyllte Aqueduct, 



which carries the Shropshire Union (late the Ellesmere) Canal 

 across the river Dee, and the Vale of Llangollen. G. R. Jebb. 



This model Avas made under the superintendence and direction of Telford 

 before the aqueduct was built. The aqueduct consists of 19 arches, each 

 having a span of 45 feet; the total length is 1,007 feet, and the height 

 from the river Dee to the surface of the water in the canal is 127 feet. The 

 foundation stone was laid on the 25th July 1795, and the work was finished 

 in the year 1803. 



This model having fallen into partial decay was a short time ago restored 

 and repainted. 



XIII. COLLECTION OF MODELS AND DIAGRAMS 

 ILLUSTRATIVE OF THE PRINCIPLES OF ME- 

 CHANICS, ROYAL SCHOOL OF MINES. 



2217. Mr. Shelley's Educational Diagrams on the Steam 

 Engine. 



2218. Educational Diagrams for illustration of Applied 

 Mechanics. 



Reciprocating motion in bul- j A parallel motion applied for 



let-making machine, rolling under pressure. 



Cams for bullet-making ma- I Pulleys connected by belts, 



chine. Angle of repose for various 



Machine for shaping plugs for substances. 



bullets. 



Screw press. 



Reversing motion in rifling | Dutch crane. 



machine (2). Differential motion. 



