The New York Rapid-transit Subway

Proceedings.] DISCUSSION ON NËW YORK SUBWAY, 113 close to the surface as the shallow subway under discussion, the Fr Copper top of the shield being about 1 metre below the roadway-paving. The method was not quite so successful there, because it was found that the effect of driving the huge shield forward with a pressure of about 300 tons was to cause a small wave in front, where the earth was forced up to a height of about 2 feet and impeded the traffic. However, there was a great difference between closing the whole street, and closing one small area about 20 yards in length. In Paris the shield had been driven along the quays from the Pont d’Austerlitz down to the Quai d’Orsay without any trouble at all, except for the momentary interruption of the particular piece of street where the shield was to run. That he thought was the only conceivable method of doing anything of the kind in London, and even of that he was rather doubtful. Mr. R. C. H. Davison thought the Author might usefully supply Mr. Davison a small Appendix showing the different steps that had to be taken to obtain powers to construct the shallow subway, and also the laws under which the works had been carried out. Mr. Macassey had men- tioned some of them, but it would be a good thing to have them all set out on paper, so as to see exactly the difference between such projects in the United States and in England. Sir William White had mentioned having seen pipes suspended from the Under side of the decking of Lower Broadway, but he had not alluded to those carried along the street-gutters, nor to those bracketed to the faces of houses. It would be interesting to know under what powers the gas-pipes were thus bracketed. In England it was a matter of the greatest difficulty to get a clause in a tramway Bill allowing the bracketing of a wire to a house; while in the great cities of the Continent they preferred to bracket things on to houses and even to suspend the electric lamps from such brackets on wires. In London the preference appeared to be for as many obstructions in the streets as possible. Quite recently a row of lamp-posts had been put down the centre of Oxford Street, dividing that thoroughfare into two narrow lanes. There was a cab-rank in Victoria Street, Westminster, that ren- dered it as quick to get along that thoroughfare by omnibus as by cab. The thing that struck him most was the great assistance given to the New York subway by the local authorities. The only assistance afforded in that way in England had been given by the City of London, which helped the Metropolitan Railway in its infancy, and assisted the Central London Railway in constructing the fine station at the Mansion House. If that assistance had been given to the tube railways of London he ventured to think that lifts would have been [the INST. C.E. Vol. CLXXIII.] I