884 



liiU'ORT -1884. 



.. 





nnd inventions, I .slioukl set myself a task whieli could not have been fiiUilJed Imd 

 I devoted tlio whole of tlie time I hud at my connnand to the purjxwe. I IkkI 

 indeed, thouirht of makiiijr his work tiie subject of my address, but I felt tlmt liis 

 loss was so recent that I could n.jt trust myself to attempt it. There is iu» need 

 for me to dwell further upon tliis most painful topic. He was known to you all 

 he was honoured and loved by you all, and by every member of tliis Assuoiation 

 lie had so faithfully served, and over whi( h he had so ably presided ; and he eiiiDved 

 tiie respect and esteem of 1 he best intelligence of England, the land of his adoptinn ; 

 ol' the ('ontinent, his birthplace; and of Canada, and of the United States, whose 

 popnlations are always ready to appreciate scientific talent and the ri'suUin<r in- 

 dusti'ial pro<rress. It is not too much to say that few move </\i\i'A men have I'ver 

 lived, and that with all his ability and talent lie combine! a simp'icity, a uiodesty, 

 and an ail'ectionate disposition that endeared him to all. 



lam sorry to concdude my address to you in this mournfi.) strain. 1 have 

 endeavoured to coniine my allusions to our dear friend within tlie narrowest 

 limits, but if I have overstepped these I trust you will forgive me, remeniberiiifr 

 that ' out of the fulness of the heart the mouth speaketh.' 





The f(dlowing' Pa])ers were read: — 



1. The Forth Brihje. By Bi:n.)Amin Bakki!, M.Inst.C.E. 



2. The Severn Tunnel liailimij. By J. Cr^ARKi: Hawksiiaw, M.Insl.G.E. 



This paper described the Severn Tumiel Itailway works, begun in Is"."!, a'.id 

 now approacliing completi(Hi. Tiie railway is being made to sliorten the direct 

 railway route between the South (if I'lngland and South Wales. It passes under 

 the River Severn about half a mile below the present steam ferry, which coniieets 

 the South Wales and Jiristol and New Passage lines. The river, or estuiiry, is 

 about i2-[ miles wide. The length of the line is 7^ miles, of wliicli 4.i miles is 

 in the tunnel which passes under the Severn. The bed of the river is formed 

 principally of Trias rocks (marls, sandstones, and conglomerates), in nearly hori- 

 zontal strata. These overlie highly inclined coal measure shales and s-indstoiiis. 

 which are also exposed in the river bed. The tunnel is made almost wliolly in 

 rocks of the Trias and Coal-measure formation, the exception being a little gravel 

 passed through near the iMiglish end. 



The lowest part of the line is below the .shoots, the deepest part of the river, where 

 there is a dejjth of GO feet of water at the time of low water, and 100 feet at tlie time 

 of high water. Pelow the shoots tiie line is level for 13 chains, rising I in MK) to the 

 English end, and 1 in 00 to tiie AVelsli tnid. IJelow the shoots there is a thicdjness 

 of 45 feet of rock (Pennant sandstone) over the brickAVork of .ne tunnel. Under 

 the Salmon Pool there is less cover, only ;5() feet of Trias marl. Much water bus 

 been met with tlirougiiout the works, which liave been flooded on several occasions. 

 In 1870, the works under the Severn were drowned for some niontiis by tiie 

 eruption of a large land spring into one of the driftways under land on the Welsh 

 side of the river. (_)n another occasion, a cavity was formed from tlie driftway 

 under the Salmon Pool to the bed of the river, when aliole, Kifeet by 10 feet, was 

 found in the marl. The works were Hooded by the water wliicli found an entry I 

 through this hole. It was idled with clay, and the tunnel is now finished I 

 beneath it. 



The quantity of water now being pumped is about 10,000 gallons per minute. 

 Additional pumps have been erected, as the large land spring, which has be.iii 

 penned back by a brick wall, still remains to be dealt with. When all the punii 

 are available, the total power will be equal to 41,000 gallons a minute. 



The tunnel is for a double Hue of way, and will bo lined throughout with] 

 vitrified bricks set in P(n'tland cement mortar. 



It is being made by tlie (ireat Western Pailway (^ompany. Sir Jcdni Hinvli- 

 ehaw is engineer in chief ; Mr. C. Richardson, engineer ; and Mr. T. A. \\'alk'r,j 

 the contractor. 



