4 BULLETIN 728, U. S. DEPARTMENT OF AGRICULTURE. 



New Mexico may be expected as stockmen learn that a number of 

 the desert plants may be used in this way and they equip their 

 ranches with the machines. 



THE MACHINES. 



From what has been said, it is easy to see that the essential factor 

 in the development of this use of an emergency feed was the produc- 

 tion of apparatus that would reduce the feed to a satisfactory mechan- 

 ical condition. While hand chopping will prepare the feed for use, 

 it is a very unsatisfactory method, because the process is slow and 

 laborious . and consequently expensive and also because the feed as 

 prepared in this way consists of chopped-up chunks of various sizes 

 which a greedy animal may swallow whole without chewing and 

 which may cause choking or impaction. A number of animals 

 have died from these causes when fed on the hand-chopped material. 



Among the stockmen who fed the hand-chopped material, one or 

 two rigged up a power pumping jack with a knife attached in such a 

 way as to cut the stalks into sections of proper size, which were then 

 chopped into smaller pieces with hand axes. On one ranch, a large 

 knife, like a tobacco-cutting knife, with a long lever operated by two 

 men, was used to cut the stalks into sections ready for the hand axes. 



A few silage cutters have been used successfully, though it is 

 necessary to chop the stems open lengthwise (they have no longi- 

 tudinal grain and therefore can not be split) before they will go 

 through the machine. 



Special power-driven machines, however, were necessary to pre- 

 pare these plants in sufficient quantity to meet the requirements of 

 the situation. 



Four such machines are now offered for sale by three different 

 manufacturing companies. These machines are all modifications of 

 a single plan. They consist essentially of a heavy cast cylinder 

 that revolves on a horizontal shaft and carries some kind of knives 

 or cutting teeth that pass close to a chopping block to which the 

 material is carried by some feeding mechanism or by gravity from a 

 hopper. 



In the largest machine the knives are like those on a silage cutter 

 or a lawn mower. Each knife* is slightly longer than the cylinder 

 and is placed diagonally across and bent around the face of it, thus 

 giving it a shearing cut as it passes the chopping block which is 

 parallel to the shaft on which the cylinder revolves. The plants are 

 fed in horizontally by a mechanism driven by gears from the cylinder 

 shaft. (PI. I, fig. 2.) A 12 to 14 horsepower gasoline engine can 

 drive this machine without any trouble and, if properly managed, 

 a crew of three men may be expected to chop from 15 to 20 tons 

 of soap weed in a 10-hour day if the plants are brought to them. 



