COMPRESSED-AIR LOCOMOTIVE. 



475 



the reservoir was about seven kilogrammes per square centimetre ; 

 the locomotive having drawn a train of twelve loaded wagons along 

 a course of about 600 metres, the pressure was found to fall to four 

 and a half kilogrammes ; the train then returned empty to the point 

 of departure, and the final pressure was found to be two and a half 

 kilogrammes. 



In spite of the relatively advantageous results which were ob- 

 tained, the employment of compressed air in a steam-locomotive pre- 

 sented a certain number of drawbacks. It is expedient that the air 



