FOREST RESEKVE MANUAL. 51 



A more accurate method than the above, but which requires 

 more work, is the estimating by strips about 4 rods wide taken 

 at frequent intervals entirely across the tract. The counting 

 and estimating of the trees is done in the same way as before. 

 These strips should always run across, not parallel with, ridges 

 and ravines, and their location on a diagram of the tract is 

 similarly required. 



When practicable, the entire-area method is preferable to 

 either of the above. In this system the entire tract is esti- 

 mated hj going through it a sufficient number of times to see 

 all the timber. To work to the best advantage, there should 

 be two men — one to keep a straight line with the compass and 

 to pace the distances and the other to estimate and tally the 

 trees. This method is especially desirable in case of surveyed 

 land, where the estimate should be made by "forties." 



In ordinary practice it is usual to cross each "forty" four 

 times, tallying by the strip method already described. It is bet- 

 ter, however, to go through each block (in the case of surveyed 

 land a quarter section) on lines not over 100 yards apart, mak- 

 ing a halt at every 100 yards, and estimating the 100-yard 

 square around this station. The figures for each square 

 should be kept separate, and the location on the diagram will 

 permit the averaging to be made for the entire block, or for 

 each "forty," as desired. 



The circle method first described should never be used in 

 large timber, or where the trees stand far apart, since the 

 area is too small to get a fair average of the number of trees 

 on an acre. 



Estimates of all tracts, whether entire blocks or areas cov- 

 ered by applications, should be reduced to average acres and 

 entered upon the blank form furnished for this purpose. The 

 size of the tract is stated in the space at the top of the blank 

 and the total stand may be computed in the office. The dia- 

 gram of the circles, strips, or squares, and the figures for 

 each, forwarded with the total estimate on the blank form 

 will enable the office, should it subsequently be desired, to 

 obtain the stand on any portion of the tract which may differ 

 from an average of the total. 



SCALING. 



Each stick of saw logs, timbers, poles, and lagging must be 

 scaled separately. Hasty methods of averaging diameters or 



