TRANSACTIONS OF SECTION G. 659 



cliaracter of the ground is such that the contingencies are small in comparison with 

 those encoimtered in the construction of the Thames Tunnel and the Hudson Eiver 

 Tunnel. Nevertheless, as I have already observed, unless special appliances of the 

 nature of the pneumatic process he used, a subaqueous tunnel, whether it be the 

 Channel Tunnel itself or one but a few yards in length, must necessarily present an 

 unknown* risk. The prototype of all these tunnels is the one commenced at 

 Rotherhithe in 1809, which was successfully driven a distance of 900 feet under 

 the Thames and failed when within little more than 100 feet of the opposite shore. 

 A tunnel about li mile in length was commenced about ten years ago under the 

 Detroit Eiver in America, but was abandoned in a similar manner. So far good 

 fortune has attended both the Severn and the Mersey tunnels, and there is, 1 am 

 glad to say, every chance of its continuing. 



That the series of mishaps with the Thames Tunnel, and the consequent post- 

 ponement of all other projects for subaqueous tunnels, were due to errors in design and 

 want of foresight on the part of the engineer is patent to everyone now, and was 

 foreseen by at least one acute contemporary of Brunei himself. Only a few months 

 ago, when turning over the leaves of an old periodical, I became aware of the fact 

 that a scheme, identical in all its main features with my Humber Tunnel project, 

 had been suggested for adoption in the case of the Thames Tunnel, in lieu of the 

 plan proposed by Brunei. Writing in December 182-3, or fifty-nine years ago, the 

 author of the project, a working smith of the name of Johnson, says : ' I propose to 

 construct the Thames Tunnel without cofferdams by making it in parts, 28 feet 

 in length, each part having the ends temporarily stopped up and beinp: coustrticted 

 on the same jn-inciple as the diving-bell. The men dig from the inside round the 

 edge as if sinking a well, and throw the earth towards a dredger, the buckets of 

 which work some feet below the bottom of the excavation. Each length will be 

 suspended between two vessels and be conveyed to the place where it is to be let 

 down.' A description of the mode of connecting the several lengths is given, and I 

 may add that the tunnel blocks had a sloping face to tend to bring the "faces of the 

 joints together, a plan smce adopted with the huge concrete blocks at Kurrachee 

 and other harbours. There is not a flaw in the design from beginning to end, as 

 modern experience in the sinking of numerous bridge-piers on precisely the same 

 plan has amply demonstrated. It is be)'ond all doubt that if the design of this 

 working smith had been adopted in lieu of that tendered by Brunei the Thames 

 Tunnel woidd have been completed in a couple of years, instead of eighteen years, 

 and at a cost of about 300/. per yard instead of 1 ,500/. 



If another tunnel be constructed under the Thames, which is far from improb- 

 able, as the requirements of below-bridge trafEc necessitate some such means of 

 communication, I venture to predict it will be built in accordance with the plan 

 suggested iifty-nine years ago by the working smith, and not on that of Brunei's 

 Thames Tunnel, or of any other tunnel yet carried out. 



At the beginning of the present century a committee was appointed to consider 

 the ' practicability of making a land communication by a tunnel under the river 

 Forth, at or near Queensferry.' In a report dated November 14, 1805, it was 

 recommended that a double tunnel should be constructed, at an estimated cost of 

 164,000/., or at the rate of .30/. per yard, exclusive of shafts and pumping. The 

 surveyors reporting, grounded their belief in its practicability upon the fact that at 

 Borrowstowness coal-workin»s had been carried under the same firth for a mile, 

 and that at Whitehaven coal was worked for the same distance under the Irish Sea, 

 in both places less watei- being met with under the sea than under the laud. The 

 report concludes in the following words : 'That a more easy and uninterrupted 

 communication betwixt every part of a country increases the intercourse of com- 

 merce, arts, and agriculture, all must know. Ferries are still and often a formid- 

 able bar in the road. Of these in this country, the one under review at Queens- 

 ferry is perhaps the most conspicuous. It is in ftrct tlie connecting point betwixt 

 the north and south of Scotland, and indeed of the realm, and in this point of view 

 the improvement of it must be considered a national object.' These words are as 

 true and applicable to the case in 1882 as they were in 1805. A ferry still is the 

 only means of communication across the Forth at Queensferry, though the traffic 



