THE SBVBEN TUNNEL. 



81 



and there ; tlien a finer gravel, and on this a clear river 

 sand. All this was quite free from mud, having been de- 

 posited in water moving too fast to let the fine mud remain. 

 Then camo silt or muddy sand, and then a layer of peat, 

 which is romarkablo in being below half-tide level, and 

 therefore many feet below the water level of every tide. 



After this camo a palo-colourcd clay, and then another 

 bed of peat, two feet thick, upon which was a blue clay up 

 to the top soil. Both these beds of peat are below the high- 

 water level of ordinary tides, and yet it is said they were 

 of fresh water origin, and the trunk of a large oak tree was 

 found buried below the upper peat bed. The beds above 

 described preserved their level — though sometimes undu- 

 lating slightly — all along tlio cutting, and must have been 

 deposited a long time ago, for there were found four river 

 courses, as the men called them (creeks or pills, as they 

 would be called here), cutting through these beds, which 

 must have indicated a former course of the Ohesscl Pill, or 

 some such tidal watercourse, for they were filled with more 

 recent Severn mud ; and this must have taken place long 

 ago, for tlioro was no indication of their position loft on the 

 surface. 



The works were all completed, and tlio Tunnel wa.s opened 

 for goods trafiic on the 1st September, and for local pas- 

 senger traffic on 1st December, 1886. 



The quantity of water now pumped from the Tunnel 

 amounts to twenty million gallons a day, of which eleven 

 millions ar'o fi'om the Sudbrook spring. This is after many 

 weeks of unusually dry weather. 



