TIMBER ESTIMATING. S7 
Except on the very smallest areas, the diameters of more than a 
}small portion of the timber are recorded but seldom, even in the 
) most accurate methods, and it is still more seldom that the height 
| of every tree will be recorded. 
A METHOD USED IN SOUTHERN YELLOW PINE. 
A method used by the Yale Forest School in yellow pine is 
| intended to combine the advantage of counting the trees on a wide 
) strip with that of a tally of the heights of a large proportion of the 
| trees. Strips on compass lines are run across the tract, on which 
| the trees are counted to a width of 10 rods. Should the crew con- 
| sist of a compass man and two cruisers, each cruiser takes a 10-rod 
| strip on one side and parallel with the compass man. 
_ In this way 20 rods are covered, and two strips, one through the 
center line of each half of 40 acres, will cover 50 per cent of the 
entire area. In ordinary pine timber the cruiser can travel along 
the outer or farther edge of his strip and thus view the timber out- 
side of the strip, not counted. In hardwoods, swamps, or under- 
brush, he takes the middle of the strip and counts to a distance of 
5 rods on each side. 
One cruiser with a compass man could cover 20 rods in open 
timber, but under all conditions could be sure of only a 10-rod 
strip, and working alone he could not cover more than 10 rods. 
One man, or two, running 10-rod strips, would have to run four 
strips per 40 to equal the accuracy of the double crew, but this 
would seldom be done. Two strips of 10 rods would give 25 per 
cent of the area. 
The compass man has the same opportunity to make a map and 
take notes on the topography as he has in other strip systems of 
estimating. The cruisers record their own tally and for volumes 
depend on a volume table based on breast-high diameter and mer- 
chantable 16-foot logs and half logs. The diameter and merchanta- 
ble height of every tree on the strip might be tallied, but it was 
found that equally accurate results were obtained on these wide 
strips by tallying the dimensions of-every fifth tree. In order to 
avoid the tendency to select too large or small a tree for tallying, 
it was the rule to tally each time the tree nearest the cruiser. 
This tallying of 1 tree in 5 instead of every tree enables the crews 
