TRANSACTIONS OF SECTION G. 867 



remained in great terror till those upon the surface succeeded in stopping the 

 water from flowing down the shaft, when a boat was obtained and the men were 

 rescued. These three disasters occurred within one week. 



The bricks used in the tunnel were all vitrified bricks from Staffordshire or 

 Cattybrook, near Bristol, or made upon the ground from shale excavated from the 

 tunnel itself, which made a stronger brick than either Staffordshire or Cattybrook. 

 The whole of the brickwork was set in Portland cement mortar mixed with washed 

 sand in the proportion of two of sand to one of cement. The laying of the per- 

 manent road through the tunnel was completed at the end of August 1885. The 

 water was finally shut out from the works on August 11, 1885. The first 

 passenger train passed through the tunnel on September 5, 1885.' 



The water from the great spring, which was blocked out of the tunnel on 

 August 11, began to rise through the ground till on October 24 it showed on the 

 pressure gauges fixed in the brickwork a pressure of 53|- lbs. on the square inch. 

 When the pressure reached this point the bricks began to fly with reports like 

 pistol shots, and to break, .so that considerable quantities of water entered the 

 timnel. The pressure rose at one time to 57 lbs. on the square inch, when Sir 

 John Hawkshaw decided that it would be unsafe to work the tunnel under so 

 great a pressure, and arrangements were made to pump the spring permanently. 



On November 22, 1886, the line was inspected by Colonel Eich, and it 

 was finally opened for passenger traffic on December 1. During the six months 

 that have since elapsed not the slightest hitch has occurred in working the tunnel. 

 The speed of the trains has often been as much as a mile a minute. 



The ventilation has been perfect, and the relief to the traffic between South 

 Wales and the south-west of England has been very sensibly felt; this traffic 

 will no doubt, with the accommodation afforded by the tunnel, be greatly increased 

 when the trains from London to South Wales run direct through the tunnel, instead 

 of, as at present, by Gloucester. 



FRIDAY, SEPTEMBER 2. 

 The following Papers were read : — 

 1. On certain Laivs relating to the Regime of Rivers and Estuaries, and on 

 the jpossilility of Experiments on a small scale. By Professor Osborne 

 Reynolds, LL.B., F.R.S.—See Reports p. 555. 



2. Improvement of the Access to the Mersey Ports. ^ 

 By W. Shelford, M.Inst.C.E. 



The author, whose attention was specially directed to the condition of the 

 Liverpool bar during the parliamentary inquiries relating to the Manchester Ship 

 Canal, aftci referring briefly to the past history of the bar, draws attention to the 

 geographical situation of Liverpool Bay as having an important bearing on the 

 proper mode of dealing with the bar. 



The tide in Liverpool Bay has a great vertical range,^ and the capacious natural 

 tidal reservoir of the Mersey causes a strong local current into and out of the bay ; 

 but there is no external or alongshore current independent of this capable of 

 removing heavy detritus to a distance, although the character of the bottom shows 

 that the finer suspended matters brought down by the river are carried away and 

 deposited in deep water. 



The reasons for the absence of such an external current are evident, since the 

 bay is not only considerably landlocked by the Welsh and Lancashire coasts, but 



' The paper has been printed in extenso in the Liverpool Daily Postoi September 

 o, 1887. 



- Thirty feet at springs. 



3 K 2 



