PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 635 



tunnel on the Great Western Railway cost $880,000 per mile ; the Salt- 

 wood tunnel on the South-Eastern, $1,038,400 per mile ; tlie Kilsby tunnel 

 on the London and North-Western, $1,114,000 per mile. When we allow 

 for finished masonry and for the difference of wages and price of materials, 

 two millions cf dollars per mile will be the more probable cost of the tunnel 

 tinder this city. 



It will not do to assume that drift gravel is the only ground to be cut 

 through, and it is a well-known fact that tunnels sometimes cost two or 

 three times more than the estimates. As a financial speculation this may 

 do, if all other improvement can be prevented; and the company can pack 

 passengers, as they are now packed in the street cars, and drive them by 

 steam ; but if every passenger is to have a seat, and improvements are 

 carried on above ground to draw a portion of the travel lo the street rail- 

 ways, this tunnel will not be profitable as a city passenger line. 



Twenty miles an hour is the speed proposed. Tiiis is too slow for trains; 

 thirty-five miles an hour is wanted. To stop and start trains at that speed 

 ■will involve the expenditure of great power, the exhaustion of great vol- 

 nmes of steam and gas, and enormous wear and tear. The momentum of 

 a train at thirty miles an hour would lift it thirty and a quarter feet high; 

 add to this the rotary motion of the wheels and axles, and the whole mo- 

 mentum would run the train a mile. Mr. A. T. Smith, superintendent of 

 the Hudson River railway, is of opinion that it costs $1.25 to stop and start 

 one of its passenger trains; and that there is a loss to the company from 

 stopping at several of the lower stations, which loss is borne because 

 people of influence insist on accommodation. The Lowell railway com- 

 pany, with lighter trains and lower speed, computed that ninety cents was 

 the cost of each stop and start. It would seem impracticable and danger- 

 ous to allow this road to be used for the heavy trains from the three great 

 railways which enter the city from the north, and to run between these 

 steam cars for carrying city passengers. But it does not appear that either 

 of the companies owning tliese railways has anything to do with this un- 

 derground scheme. It may be that the proposed branches to the stations 

 of these railways are to be built by the tunnel company for the purpose of 

 securing the passengers from abroad. The speaker regarded the tunnel 

 plan as the poorest among the improvements proposed for increasing the 

 speed of travel. The other plan, explained before the Polytechnic at a 

 previous meeting, for an elevated railway, passing over the cross-streets 

 at such a bight as not to interfere with travel, he believed would be better. 

 If such great speed is needed on the streets, steam-driven cars on the 

 street rails, or steam carriages on the street pavement, would be better 

 than the underground plan. A dark passage poisoned with carbonic acid 

 and humid with vapor is not fit for civilized men to travel in. 



In regard to road surfaces there has not been an improvement since 

 the Roman Empire. The modern innovation, the broken stone system of 

 McAdam and Telford, is in no sense an improvement. It is indeed more 

 pleasant to ride upon than the paved roads of France; but compared with 

 the stone tracks of Lombardy, or the pavement of Naples and Tuscany, it 

 is less pleasant, more difficult of traction, subject to atmospheric influences, 

 and far more expensive. It was stated before a committee of Parliament, 



