of the trains, in the agitation of the air, in the action of the friction of the brake shoes upon the wheels, of the pounding of the wheels upon the rails and other such mechanical evidences of heat, all of which are supplemented by the heat of the electric lights and the body heat from the passengers, etc. etc. The result of all this excess heat produces a condition which, in warm weather at least, is considered by the public at large as "most uncomfortable."
First Alterations
By reference then to Diagram A it will be noted that the subway had been opened for probably six or eight months before any alteration or addition was made to remedy defective ventilation.
While Prof. Soper was conducting his investigations, Chief Engineer Rice was beginning to make certain alterations which it was assumed would help, if they did not entirely remedy the evils complained of. From a construction standpoint then, the subway consisted of a continuous underground tube with a number of perforations in its envelope between the two terminals which perforations were the passenger stations, nor were there any other vent openings provided. We now find that the engineers proceeded on the assumption that by punching additional holes preferably in the covering of the subway, the excess heat would escape to the atmosphere. This could only take place if such a perforation is connected to a fan or chimney which will produce a draft and as this was not done naturally no benefit followed. In addition to this, the Chief Engineer not only suggested refrigeration of the air, but actually made quite an extensive attempt to do this at the Brooklyn Bridge station. Undoubtedly, many have noticed the fan chamber and ducts, and other evidences of this so-called refrigerating scheme, but may not have known what it was intended for. The method followed consisted of driving a well to a considerable depth from which relatively cold water was obtained. This being pumped to the surface was sprayed through nozzles and air from the station was drawn in by fans and was forced through this mist of water and thereby somewhat cooled, whereupon the air was forced out through ducts to lower the rising temperature of the waiting passengers at the stations. When one realizes that in the old subway from the Brooklyn Bridge to Columbus Circle a length of 4½ miles, there is something like 27,000,000 cubic feet of air to be cooled by an amount equal to 85% of all the heat energy generated at the central stations, one does not have to be a scientist or an engineer to see the utter futility of such a scheme and the very statement of the attempt is a sufficient criticism of it.
This cooling plant was completed and put into commission on Aug. 29th, 1906 (see pages 197 to 203 of the report). Prof. Soper's investigations cover a period between July 1st, 1905, and Dec. 31st,
