pROCEtlDINGS OF THE POLYTECHNIC ASSOCIATION. 701 



slide along and not injure passengers, because their wheels will be 

 free from the friction caused by flanges, cones and false shapes caused 

 by wear, -and because they will use less power than heavy trains, and 

 may, therefore, drive their fires all the time, in cases Avhere heavy 

 engines have to shut their' dampers and exhaust into their tanks, as in 

 the tunnels of the Metropolitan railway. 



On this line, a train weighing 122 tons, with an average of fifty- 

 five passengers (125 tons total), starts every five minutes. The 

 stations are half a mile aj^art ; and, with trains so frequent, each must 

 stop at all stations. The power required to start every half mile is so 

 great as to double the consumption of fuel that would be required 

 for running through ; yet the number taken at a way station could 

 often be taken by a carriage weighing a twentieth as much as the train. 

 The result of this great waste of power, and restraint on making 

 steam, is that the speed averages eleven and three-quarter miles an 

 hour. A higher speed could be got if they could make steam all the 

 time; but, even then, the frequency of the stops would prevent so 

 high a speed as is needed. It is claimed that steam-carriages, on iron 

 fioors that are as true as rails, can run faster than ordinary railway 

 trains ; and can economically average thirty miles an hour for the 

 long trafiic, and can save much expense on the short traffic. 



The average weight per passenger on the Metropolitan, is 5.108 lbs. 

 An eiglith of this is deemed a fair allowance for steam-carriages that 

 may be run in greater or less numbers at difiereut hours of the day, 

 as trafiic requires, and that can tlius be made to average half-loads. 

 And the consumption of fuel, and consequent difiiculty about the 

 atmosphere in a tunnel, or close way, will be in proportion to the 

 total weight moved. 



The chairman spoke of the three most prominent plans for railway 

 transit through the city of New Yoi-k, namely : The tunnel railway, 

 tlie elevated road, and the Arcade plan. 



Mr. James Montgomeiy spoke at length of these plans, condemn- 

 ing the underground plan, on account of the large amount of carbonic 

 acid gas, which would be always in the tunneh 



Mr. Melville C. Smith stated that the Legislature appointed a com- 

 mittee to come to this city to examine the best means of relieving 

 this city, and the most feasible means of transit to the upper end of 

 the island. The result was, about forty plans were submitted to 

 them, only five, of which seemed to be practical. After a careful 

 investigation of all the facts, the committee decided that there was 



