134 THE BRIGHTON ROAD 



Lunatic Asylum, through which it runs in a covered 

 way, the London County Council, under whose control 

 that institution is carried on, obtaining a clause in 

 the Company's Act, requiring the railway to be 

 covered in at this point, in case the lunatics might 

 find means of throwing themselves in front of passing 

 trains. 



Leaving the asylum grounds, the railway re-crosses 

 the road by a hideous skew girder bridge of 180 feet 

 span, supported by giant piers and retaining- walls, 

 and then crosses the deep cutting of the South Eastern, 

 to enter a cutting of its own leading into a tunnel a 

 mile and a quarter in length — the new Merstham 

 tunnel — running parallel with the old tunnel of the 

 same name through which the South Eastern Railway 

 passes. At the southern end of this gloomy tunnel is 

 the pretty village of Merstham, where the hillside 

 sinks down to the level lands between that point and 

 Redhill. 



At Merstham one of the odd problems of the new 

 line was reached, for there it had to be constructed 

 over a network of ancient tunnels made centuries 

 ago in the hillside — quarry-tunnels whence came much 

 of the limestone that went towards the building of 

 Henry VII.'s Chapel at Westminster Abbey. The 

 old workings are still accessible to the explorer who 

 dares the accumulation of gas in them given off by 

 the limestone rock. 



The geology of these five miles of new railway 

 is peculiarly varied, limestone and chalk giving j)lace 

 suddenly to the gault of the levels, and followed again 

 by a hillside bed of Fuller's earth, succeeded in turn 

 by red sand. The Fuller's earth, resting upon a 

 slippery substratum of gault, only required a little 

 rain and a little disturbance to slide down and over- 

 whelm the railway works, and retaining- walls of the 

 heaviest and most substantial kind were necessary 

 in the cuttings where it occurred. Tunnelling for a 

 quarter of a mile through the sand that gives Redhill 

 its name, the railway crosses obliquely under the South 



