742 Transactions of the American Institute. 



plislied at all, when steam is used, without especial and expensive 

 contrivances. This question will determine better than anything 

 else what kind of a road is best for tliis city. The underground 

 street, or coml>ination of tunnels, bridges, and open cuttings, is the 

 surest of success, because already in pi-actical operation elsewhere. If 

 land is too valuable to adopt this plan, then a regular system of ven- 

 tilation must be worked out for covered ways, so that steam may be 

 employed, or, better still, the system of propulsion by compressed 

 air should be established on a proper scale, which will also ventilate 

 and cool the tunnel. 



Dr. W. Rowell remarked that ice was very essential in ventilation, 

 especially in a room. He proposed to have a large dish tilled with 

 ice about a foot above the floor ; this would permit condensed air to 

 come into the room. With ten cents worth of ice a room of twelve 

 feet square could be made quite comfortable for an evening. 



Dr. L. Bradley in further elucidation of his views expressed at a 

 previous meeting read the following paper : 



The Tunnel Railway. 



It will be recollected that, at a previous meeting, the plan which I 

 proposed as feasible for the relief of Broadway, and to facilitate com- 

 munication through the great city of New York, was derided by cer- 

 tain individuals as being visionary and impracticable, especially when 

 I claimed that, Avith ample means and men, provided beforehand, the 

 work could be accomplished in six month's time. 



It seems, therefore, proper I should now give a few estimates and 

 figures, such as I have been able to obtain from unquestionable 

 authority, to show not only the practicability, but the entire feasi- 

 bility of the plan. 



I proposed to construct a tunnel, not under any particular street, 

 but upon a straight line from South Ferry to Harlem bridge, which 

 will pass directly under corner of Broad and Pearl streets, eastern 

 part of the park, diagonally under Elm and Crosby streets, under the 

 angle of Broadway at 10th street ; thence diagonally across -ith ave- 

 nue and parallel with 4t!i avenue, midway between that and Lexing- 

 ton avenue, and following the same line to the bridge. 



I proposed to put it at a level, beneath all cellars, sewers, mains, 

 etc. To be thii-ty feet wide and to average twelve feet from the top 

 to the bottom. 



I proposed at the way stations, at every 832 feet, to sink a shaft on 



