10 



PEACTICAL PART 



PT. 1. 



Place the upper surface of the ball of earth at 

 precisely its former level, and do not cover it ; but 

 raise a very slight ridge of earth round the outside of 

 its circumference, so as to form a pan or irrigation cup. 

 Tie some bushes round the stem to prevent cattle from 

 rubbing it. The organisation of the bark is easily 

 mechanically injured and destroyed by any bruise, or 

 by cattle rubbing against it. It is the common error 

 to believe that the bark is chemically poisoned by the 

 oil from the skin of cattle. 



It may be found necessary to stay the sv^ay of the 

 tree, while in movement, by ropes from the stem to the 

 shafts. 



In going dov\rn steep hills the machine may be held 

 back by a horse ridden behind, and hooked on by the 

 South American surcingle and single trace ; or the 

 machine may be very conveniently blocked by lashing 

 a bar of wood across the shafts, close in front of the 

 wheels, and taking out the screw which fastens the 

 shafts to the axle. The horse will then bear back 

 against the wheels instead of against the axle, and the 

 Iriction against the wheels will increase or decrease 

 directly as the downward impetus. 



This application of a common mode of blocking 

 wheels has the advantage of being entirely self-acting. 

 It needs neither the attention nor personal service of the 

 driver ; nor is it left to his judgment at what time, or 

 how much, or how little, to put on or to take off. 

 Without any stoppage or trouble, friction is acquired 



