30 
BULLETIN 1402, V. S. DEPARTMEXT OF AGEICrLTURE 
up to 125 feet above the groiincL This, of course, gives a lifting 
effect on incoming logs, the degree varying inversely with distance 
from the spar tree. Loggers generally estimate that the lift dis- 
appears at a distance from the spar tree of five times its height. 
The high-lead system, especially ^vhen high-speed engines are used, 
results in very serious damage, particularly in the zone surrounding 
the setting, and tliis is ajDparently inherent in the method. (Fig. 10.) 
The tightening up on the line in changing snaps out the tops of many 
saplings, poles, and potential seed trees, while the lift on incoming 
logs means that they hit obstacles, among which are trees, higher 
above the ground than with the ground lead, and many of the pos- 
sible seed trees are broken off or pulled down in this manner. The 
Fig. 10.— a BARREN SWATHE LEADS UP TO THE SPAR TREE 
The terrific power of high-lead yarding Tripes out young growth and smashes seed 
trees where the trails converge. Where future productivity of the land is hoped 
for, this form of yarding is highly unprofitable. 
high lines result in stripping the crowns, a more serious form of 
injury than trunk wounds, from the standpoint of immediate growth. 
In typical ground-lead yarding the line is changed as infrequently as 
possible, and it follows that a relatively small percentage of the total 
ground area is dragged by incoming logs. AVith the high lead, on the 
contrary, fewer logs come in over a single trail and logs do not hold 
to established trails, so that a much higher percentage is dragged, and 
the damage to reproduction and even to trees up to 10 and 12 inches 
in diameter at breast height varies on the average directly as the area 
covered by log trails. 
Comprehensive data obtained by E. X. ]Munns on several tyj^ical 
high-lead settings are summarized in Table 2. 
