1484 



AMERICAN FORESTRY 



scale of logs in the whole tree. The tree has, in the mean- gers liavi- \vd many cruisers into the habit of working on 



time, been scanned for signs of defect, or otitward indi- rather a wide margin. (Jften a man who has timber to 



cations calling for a reduction in the scale. When svich a sell. is. of course, eager to see as high a cruise as possi- 



suitable deduction has been made, the final result should ble on his timber land. On the other hand, a lumberman 



be close to the actual lumber content of the tree. This, who wants a report on timlier which he intends to buy 



however, is a slow process, and not many cruisers take and operate, demands a considerable margin of safety and 



time to do the work so thoroughly. After the eye has consecjuently thinks most highly of the cruiser who turns 



become trained to sizes and lengths, a somewhat pro- in a fi^nre well below what he will cut of¥ the tract when 



longed glance at a tree en- 

 ables the cruiser to make 

 u]) his mind as to the scale 

 of the logs, and the amount 

 for the tree is ])ut 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 sami)le ])lots. 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 sami)le of the stand is 

 obtained, and when this has 

 been done 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 pro])ortion of a "forty" 

 or a quarter-section, or a 

 S(|uare-miie section has 

 been covered, the average 

 is ap])lied to the whole 

 area. When the sample 

 plot method is adopted, the 

 sample jjlots are generally 

 laken in one-half acre cir- 

 cles. ;ni(l located at regular 

 intervals on the cruise 

 Hues. The strip method is 

 more satisfactory, however, 

 and is much more widely 

 used. 



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he operates. This has re- 

 sulted in an uncertainty 

 among timbermen and in- 

 vestors as to the validity of 

 crtiise 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 "timljer 

 cruise" into a "forest sur- 

 vey.'' The chief points of 

 (lifiference between the two 

 are that the forest survey 

 includes topographic (con- 

 tour) maps, based on a 

 series of systematically lo- 

 cated compass lines, and a 

 more extensive tise of 

 uieasurcmenis as a basis 

 for determining volume in 

 board feet. 



77k' 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 



The results of the work of the timber cruiser range patchy timber, a closer spacing is obviously desirable, 



from simi)le columns of figures giving the kinds and Likewise for large areas with extensive uniform timber 



quantities of timber, to a fairly elaborate map with types, wider spacing may be used. Complete record is 



elevations marked, and cruise figures recorded directly on taken of all stream crossings, rock outcrops, elevations, 



the map, accompanied by a written report. Methods of etc., and the timber is tallied for 33 feet (one-half chain) 



field work and form of presenting results vary widely on each side of the line. 



according to the personal experience, character, and If the sjiacing of cruise lines is 10 chains apart, the 



ability of the individual cruiser. ])arallel cruise lines (on which a complete tally of timber 



The demands of timber owners, lumbermen and log- and other data are taken) will, of course, occupy 10 per 



