1904.] DUDLEY — PASSENGER CAR VENTILATION. 255 



In explanation of the figures it may be stated that the stations 

 mentioned denote locations at which air samples were taken. 

 Bennington, on the schedule used, is about twenty-three minutes 

 from Altoona ; Buttermilk Falls is about fifty-seven minutes from 

 Bennington, and Johnstown is about ten minutes from Buttermilk 

 Falls. Returning, Cresson is about forty-two minutes from Johns- 

 town; McGarvey about twenty minutes from Cresson, and Altoona 

 about five minutes from McGarvey. These figures will give some 

 idea of the interval between samples. 



As has already been stated, the system was designed to give 

 60,000 cubic feet of air per car per hour, and it was felt that the 

 figures given above show that the system fairly well fulfills the pur- 

 pose for which it was designed. Not more than 60,000 cubic feet 

 were planned for, for the reason that it was found impossible, as the 

 result of experiments made early in the studies on this subject, to 

 warm the large amount of air required by theory. While it would 

 perhaps be possible to warm more than 60,000 cubic feet of air, yet 

 it is always desirable to have some little factor of safety in the 

 appliances used, and accordingly, after very careful consultation 

 over the matter, it was decided not to attempt to get more than 

 60,000 cubic feet per car per hour. 



Two points iurther were made the subject of test : First, the 

 ability to keep the cars warm, even in the severest weather. This 

 with the heating system, for which the ventilating system was 

 designed, was found to be extremely satisfactory. Careful obser- 

 vations were made both on long runs and during severe cold 

 blizzards on this point by competent persons, and at no time has 

 there been any difficulty in keeping the car comfortable. Further- 

 more, the distribution of the heat in the car seems to be entirely 

 satisfactory. Even under the influence of severe winds, not more 

 than two or three degrees difference in different parts of the car 

 are observable. It may be worth while to mention that, as will be 

 noted from the description, the ventilating system consists of two 

 halves, which are entirely independent of each other, except that 

 the heating system on the two sides takes steam from the same 

 point. Careful experiments with cars on the road indicate that 

 when the wind is directly ahead, the two sides of the car take in 

 approximately equal amounts of fresh air. When the wind, how- 

 ever, is to the right of the line of motion of the car, that side of 

 the car seems to do most of the ventilating, and when it is to the 



