TRANSACTIONS OF THE SECTIONS. 157 



by the most eminent and experienced geologists and miners. No sucli 

 system' has yet been pursued in this country ; and the importance of 

 the subject renders it deserving of the attention of the British Associa- 

 tion during its meeting in the midst of the mining districts of the north 

 of England. 



Mr. Sopwith's paper proceeds to point out the inconveniences and 

 serious loss of capital, and even of human life, resvilting from the pre- 

 servation of mining records being neglected, and to explain several 

 practical details connected with the subject. 



On Improvements in Ship Building. By Mr, Lang. 



Mr. Lang described and exhibited some models illustrative of the 

 safety keel, which had been introduced with great success ; and men- 

 tioned instances in which vessels fitted with these keels had struck and 

 come off without sustaining material injury. He then entered into 

 some details respecting the proper construction of merchantmen, and 

 exhibited some models of the bottoms of merchantmen*. He also ex- 

 hibited a method of securing a round-headed rudder, and a model of a 

 tube-scuttle to admit light between decks, and which had. been used 

 with great success. 



On the Construction of a Railway with Cast-Iron Sleepers, as a Sub- 

 stitute for Stone Blocks, and xoith continuous Timber Bearing. By 

 T. Motley. 



The cast-iron sleepers, which are wedge-shaped and hollow, having 

 all their sides inclined inwards toM'ards the under side, are to be laid 

 transversely, and the timber is to pass longitudinally through the 

 centi-e, and to be secured by wedges of iron and wood. The sleepers 

 are to be six inches apart, and the timber of such a thickness as to 

 prevent any perceptible deflexion betwixt the rails. The road is to be 

 ballasted up to the top of the sleeper, and the timber to stand out suf- 

 ficiently, and to have any approved rail laid upon it. 



On a Suspension Bridge over the Avon, Tiverton. By T. Motley. 



The peculiar feature of this bridge is, that each chain is attached to 

 the roadway, and the suspending bars are carried up through each 

 chain above it. The length of the bridge is 230 feet, the breadth 14 feet, 

 and the cost, including the towers and land abutments, under 2400^. 

 This bridge is superior to the common suspension bridge, in that it is 

 more firm, and experiences much less friction, owing to the absence of 

 vibration. 



* See Reports of the British Association, vol. vi. p. 135. 



