Page:Popular Science Monthly Volume 10.djvu/491

This page has been validated.
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.

Fig. 2.—Compressed-Air Locomotive Used at the St. Gothard Tunnel Works.

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