.269 



the position indicated on the Ordnance Map, and a little west 

 of the spot where the G.W.R. crosses over the Tunnel which 

 now enters the Great Oolite, through which it passes for a 

 distance of about 1120 yards, to the Coates or eastern face. 



The Great Oolite beds may be readily inspected at the valley 

 shaft, and in the various lengths of rocking left between the 

 arching, as shown on the section. 



The general dip of these beds is very slight towards the south- 

 east, except at the first rocking, east of the long arching, where 

 it is very decided (in that direction) ; but past the shaft, at the 

 crossing of the G.W.R., it is for a little distance in the opposite 

 direction, so that it is slightly synclinal, following in a modified 

 way the surface formation of the valley above, through which the 

 Eailway passes. The structure of the Cotteswold ridge at 

 Sapperton has been further illustrated by the construction of 

 the G.W.E. Tunnel, which was carried out by Mr. E. P. 

 Breeeton, Mem. Inst., C.E., between 1843 and 1845, (then 

 acting as Assistant Engineer to the late Mr. I. K. Bettnel.) 



That Tunnel was originally designed at a lower level than 

 ultimately was adopted, — shafts were sunk, and a heading 

 upwards of one mile in length was di-iven through the Hill, — 

 between 1837 and 1841, when it was found necessary to reduce 

 the expenditure required for the construction of the Cheltenham 

 and Great Western Eailway in every possible way, in order 

 to get the Eailway completed and opened for traffic; and, 

 amongst other things that were done, the late Mr. Bettnel's 

 first idea of a longer Tunnel at Sapperton Svunmit, with a 

 better gradient up the Stroud Valley than has been formed, 

 was modified, and the Directors of the Company determined 

 to raise the level of the Summit Tunnel and make it much 

 shorter. Hence the present Tunnel and defective gradient 

 leading to it from Stroud.* But the effect of the operations of 



* The Eailway Company obtained tteir Act of Parliament in 1836, and 

 opened a part of their Line between Swindon and Cirencester, first (about 

 1841;) afterwards on May 12th, 1845, they opened it between Kemble and 

 Gloucester. Mr. Jonathan NowEii was the Contractor who constructed 

 tiie Railway Tunnel. 



