Geology of Wiltshire. 329 



Comoseris, Cladophyllia, Thamnastrea, Isastrea, &c., and in greater numbers 

 than in any other part of either of the adjoining strata. After a heavy rain 

 the sides of the railway cutting afford a very interesting view of the fossil 

 fauna of the period. 



2 The Box Tunnel was chiefly formed through the Great Oolite and Fuller's 

 Earth. An account of the works, written by a late member of our Society, in 

 1839, and published in a local journal of that date, contains some particulars 

 which will be worthy of record in the Wiltshire Magazine. One of the 

 greatest obstacles to the construction of the Great Western Railway was found 

 to exist in Box Hill, a large extent of elevated ground lying directly between, 

 and about equidistant from, Chippenham and Bath. This hill, the highest part 

 of which is about 400 feet above the proposed level of the railroad, could not 

 be avoided : to make an open cutting through it was impossible, and to per- 

 forate it was thought by many equally so. Nevertheless, Mr. Brunei, with 

 that boldness for which he was so celebrated, adopted the latter plan, and 

 accordingly it was determined that a tunnel, one mile and three quarters 

 in length, 40 feet in height, and 30 feet in width, should be made through the 

 hill. The extraordinary attempt of boring through this immense mass, con- 

 sisting in great part of beds of solid freestone, was commenced in the summer 

 of 1836 and completed in 1841. The difficulties that stood in the way of the 

 performance of this great work, particularly that part of it on the east, were 

 appalling; but they have been surmounted by the enterprise, skill and per- 

 severance of Mr. Brewer of Rudloe, and Mr. Lewis of Bath, the gentlemen 

 who contracted with the Directors for the completion of that portion of it. 

 Independently of the difficulties arising from the laborious nature of the 

 undertaking, the constant flow of water into the works from the numerous 

 fissures in the rock, has been constantly most annoying; and in the rainy 

 season so formidable as almost to destroy all hope of being able to contend with 

 it. In November, 1837, the steam-pump then employed being quite inadequate 

 to the task of making head against it, the water increased so fearfully — having 

 filled the tunnel and risen to the height of 56 feet in the shaft — as to cause the 

 total suspension of the works till the July following. This would have caused 

 many persons to have abandoned the work in despair ; but Messrs. Brewer & 

 Lewis, determined to fulfil their contract if possible, erected a second pump, 

 worked by a steam-engine of 50-horse power, and had the satisfaction of van- 

 quishing their enemy, and resuming their work. A few months afterwards (in 

 November, 1838) the works were again stopped by an influx of water, which, 

 however, was got under in ten days, the engine discharging 32,000 hogsheads 

 of water in a day. In the poition of the tunnel between the seventh and 

 eighth shafts (1520 feet in length), Messrs Brewer & Lewis commenced their 

 operations at each end, working towards a centre ; and when the two cuttings 

 closely approximated, much anxiety was felt lest a straight line should not have 

 been kept, and the union of the two portions of the work should not have been 

 true. But, on breaking through the last intervening portion of rock, the 

 accuracy of the headings was proved, and to the joy of the workmen, who took 

 a lively interest in the result, and to the triumph of Messrs. Brewer & Lewis's 

 scientific working, it was found that the junction was perfect to a hair as to 

 the level, the entire roof forming an unvarying line ; while laterally, the utmost 



