1484 



AMERICAN FORESTRY 



scale Of logs in the whole tree. The tree has. in the mean- 

 time, been scanned for signs of defect, or outward indi- 

 cations calling for a reduction in the scale. When such a 

 suitable deduction has been made, the final result should 



be close to the actual lumber content of the tree.' This, 

 however, is a slow process, and not many cruisers take 

 time to do the work so thoroughly. After the eye has 

 become trained to si/.es and lengths, a somewhat pro- 

 longed glance at a tree en- 

 ables the cruiser to make 

 up his mind as to the scale 

 of the logs, and the amount 

 for the tree is put down in 

 round numbers. Many 

 cruisers' also note the per- 

 centage of grades, either of 

 logs or lumber. 



Trees are tallied in this 

 way, over certain areas, 

 either in the form of strips 

 or sample plots. The trees 

 are tallied on a strip by fol- 

 lowing a straight compass 

 line, and including all the 

 trees for 33 feet (one-half 

 chain) on both sides of the 

 line, so that a one-chain 

 wide sample of the stand is 

 obtained, and when this has 

 been clone for a distance of 

 ten chains, the trees on one 

 acre have been tallied as to 

 board feet contents. The 

 average stand for a num- 

 ber of acres is obtained in 

 this way, and when a cer- 

 tain proportion of a "forty" 

 or a quarter-section, or a 

 square-mile section has 

 been covered, the average 

 is applied to the whole 

 area. When the sample 

 plot method is adopted, the 

 sample plots are generally 

 taken in one-half acre cir- 

 cles, and located at regular 

 intervals on the cruise 

 lines. The strip method is 

 more satisfactory, however, 

 and is much more widely 

 used. 



The results of the work of the timber cruiser range 

 from simple columns of figures giving the kinds and 

 quantities of timber, to a fairly elaborate map with 

 elevations marked, and cruise figures recorded directly on 

 the map, accompanied by a written report. Methods of 

 field work and form of presenting results vary widely 

 according to the personal experience, character, and 

 ability of the individual cruiser. 



The demands of timber owners, lumbermen and log- 



"CYPBESS" OR VKLLOW CF.DAH 

 BALSAM FIR 



gers have led many cruisers into the habit of working on 

 rather a wide margin. < >ftcn a man who has timber to 

 sell. is. of course, eager to see as high a cruise as possi- 

 ble on his timber land. On the other hand, a lumberman 

 who wants a report on timber which he intends to buy 

 and operate, demands a considerable margin of safety and 

 consequently thinks most highly of the cruiser who turns 

 in a figure well below what he will cut off the tract when 



he operates. This has re- 

 sulted in an uncertainty 

 among timbermen and in- 

 vestors as to the validity of 

 cruise reports in general, 

 because of extreme varia- 

 tions in reports on the same 

 tract, due to variability in 

 standards and methods. 



What the cruising pro- 

 fession has lacked is engi- 

 neering training with its 

 resulting standardization of 

 methods. The forest en- 

 gineer, who is the modern 

 timber cruiser, has 

 brought his technical train- 

 ing to bear or. the problem, 

 and expanded the "timber 

 cruise" into a "forest sur- 

 vey." The chief points of 

 difference between the two 

 are that the forest survey 

 includes topographic (eon 

 tour) maps, based on a 

 series of systematically lo- 

 cated compass lines, and a 

 more extensive use of 

 measurements as a basis 

 for determining volume in 

 board feet. 



The first necessitates the 

 establishment of base lines, 

 carefully chained and level- 

 ed, and marked at five or 

 ten-chain intervals for 

 cruise lines. (See sketch 

 plan. ) The cruise lines are 

 run from one base line to 

 the other at whatever in- 

 tervals have been decided 

 on. usually ten chains apart. 

 For smaller areas and 

 patch}- timber, a closer spacing is obviously desirable. 

 Likewise for large areas with extensive uniform timber 

 types, wider spacing may be used. Complete record is 

 taken of all stream crossings, rock outcrops, elevations, 

 etc.. and the timber is tallied for t,^ feet (one-half chain) 

 on each side of the line. 



If the spacing of cruise lines is to chains apart, the 

 parallel cruise lines ( on which a complete tally of timber 

 and other data are taken ) will, of course, occupy 10 per 



ON LEFT AND PACIFIC COAST 

 N THE RIGHT 



