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 obtained, the employment of compressed air in a steam-locomotive presented a certain number of drawbacks. It is expedient that the air