178 POWER AND THE PLOW 



case would run directly in front of the plow point. The idea 

 would of course be impracticable for travelling on hard or 

 sticky ground, but it illustrates well the conflicting require- 

 ments. 



STEAM-LIFT PLOWS 



Steam-lift plows differ from the large hand-lift gangs in that, 

 in place of a platform and lifting levers, they are equipped with 

 steam cylinders for lifting the plows. Steam is fed from the 

 engine through flexible connections and the plow may be con- 

 trolled by the engineer without his leaving the cab. From 

 four to six plows are lifted by each cylinder, which operates a 

 boom attached by short chains to the plows. Some types can 

 be backed into position for turning a square corner by means 

 of a steering wheel connected by crossed cables with the front 

 axle of the engine. If one of the enginemen can be spared 

 occasionally to look after the plows in case of trouble, the 

 plowman may be dispensed with entirely. Owing to the 

 added cost of manufacture, the use of the steam-lift feature 

 has been confined to the larger sizes of from eight to twelve 

 bottoms. The steam-lift plow uses considerably more coal 

 and water, is more complicated than the hand-lift, takes longer 

 to attach and detach, and exposes operators to the danger of 

 being burned on hot steam pipes. With the coming of the 

 large hand-lift gang several manufacturers abandoned the 

 steam-lift feature, but various types of power-lift plows, includ- 

 ing steam-lift, are constantly being brought forth with a view 

 to reducing the labor of attendants. A simple and inexpensive 

 device which would eliminate the plow attendant is demanded 

 by the trade, especially in the sections where small tractors 

 prove the most useful. 



DISK-ENGINE PLOWS 



Disk-engine gangs are made in sizes of from three to twelve 

 disks. The smaller sizes lack compactness, and the larger 



