TIMBER ESTIMATING IN THE SOUTHERN APPALACHIANS 313 



when spruce and some other special types occur, or when the cove 

 and lower slope timber runs so high on the slopes that it is most 

 convenient to continue the strips straight across the narrow belts 

 of poor timber on the ridges. However, it is more usual to find the 

 timber concentrated in the coves, separated by rather broad, sparsely 

 timbered areas on the upper slopes and ridges, and under such con- 

 ditions it is plain that the conventional system of parallel, equidistant 

 strips is not economical. If the strips are run close enough together 

 10 give a good estimate of the heavily timbered cove stands, they 

 will be much closer than necessary on the scantily timbered upper 

 slopes and much time and labor will be wasted. The problem is to 

 modify the system so as to tally a high per cent of the good stands, 

 and a low per cent of the poor. This may be done by covering the 

 entire tract with a regular gridiron system of strips 20 to 40 chains 

 apart, as circumstances may require, and making an additional tally 

 in the cove, or cove and lower slope, stands by one of the following 

 methods : 



1. Additional strips may be run between and parallel to the grid- 

 iron system. This is practicable only in rare cases where the 

 coves are extremely wide, as in hollows of ordinary width it would 

 involve a great waste of time in offsetting. 



2. Zigzag strips may be run along the hollows, continuing on 

 each course until the extreme edge of the type is reached, and then 

 changing the direction so as to cross the hollow again. This method 

 gives an additional tally of the good timber without loss of time in 

 offsetting. It is adaptable to varying requirements, for a larger or 

 smaller proportion of the type can be covered by increasing or decreas- 

 ing respectiv'ely the angle between the courses. On the other hand, 

 if it is desired to maintain approximately the same per cent in hollowv? 

 of unequal width, this can be accomplished by making the change of 

 direction at turning points small in narrow places and large in wide 

 places. It is usually most economical to run the zigzag strips two 

 chains wide, using a three-man crew. One estimator calls the trees 

 on one side of the line .and maps, while the other works on the 

 opposite side and snubs chain. The compassman tallies, and runs 

 a rough box compass traverse, giving the courses to the map maker. 

 The most experienced estimators in the party should, of course, be 

 used on the "zigzag" crew, since they are working wholly in the 

 commercially valuable timber. Ordinarily, a 20 to 30 per cent tally 



