256 DUDLEY— PASSENGER CAR VENTILATION. LApril 8, 



left, that side does the most of the ventilating. This will be 

 readily understood from the construction. The curvature of rail- 

 roads, however, is so great that this fluctuation in the amount of 

 fresh air taken in on the two sides does not, as already stated, 

 seriously affect the temperature in different parts of the car. 



The final test made has been as to the ability of the ventilating 

 system to exclude objectionable matter, such as smoke, cinders and 

 dust. A good deal of interest was felt over this matter at the 

 start, and it is to be confessed that anything which is fine enough 

 to be carried in the air will ultimately find its way into the car. 

 As a matter of fact, it is found that small cinders which pass the 

 gauze on the hood of the in-take are distributed more or less along 

 the bottom of the space underneath the floor, and it occasionally 

 becomes essential to clean these cinders out. Also in going through 

 tunnels, sometimes smoke and gases are taken into the car in small 

 amount. To meet this difficulty a butterfly valve was put in the 

 down-take, and the instructions provide that this shall be closed 

 when going through tunnels. Furthermore, the air being taken from 

 near the top of the car, dust rarely gets high enough to cause any 

 trouble. Smoke from the locomotive usually is either diverted by 

 the wind, or is high enough not to reach the in-takes, so that, as a 

 matter of fact, less difficulty has been experienced from objection- 

 able material going in along with the fresh air than was feared. 

 Finally, the air in the car being completely changed once in four 

 minutes, it is evident that the inconvenience from temporary foul 

 air going into the in-takes is reduced to a minimum. 



The system as described has been in daily use on more or less 

 cars, for now some five years, and the criticisms leading to modifi- 

 cations have been less than might have been expected. The system 

 is being applied to all new cars as fast as they are built, and to other 

 cars in the equipment as fast as circumstances will admit. It is 

 unfortunate to be compelled to say that the system has not yet been 

 applied to a sleeping car. 



Altoona^ Fenna.y April 7, 1^04. 



