4 



In mcasurfng logs and trees the following genera! rules are laid 

 down for foresters on the continent of Europe : — 

 {a) Diameters are to be preferred to girths. 



(b) In the case of elliptical or oval stems, take the mean of the 



largest and smallest diameters. 



(c) In the case of large stems measure at least two diameters. 



(d) In the case of stems of irregular contour, measure several 



diameters, and avoid all protuberances, etc. 



(«) Measure diameters and girths always in a plane at right 

 angles to the axis of the stem. 



(/) If the place of measurement falls on an irregular part of 

 the stem, measure the diameter or girth, as the case 

 may be, at an equal distance on either side (above and 

 below) of the irregularity, and take the mean of the two 

 measurements. 



{ff) Moss, etc., thick enough to vitiate the measurement of the 

 stem should be removed. 



{A) If an accurate measurement of an irregular section is re- 

 quired, transfer its outline to tracing paper and compute 

 its area with a planimeter or acre-comb. 



(t) Never be without tables showing at a glance the areas of 

 circles for given diameters and girths. 



In England and India diameters are rarely measured, as old 

 established custom has i)rescribed that in the sale of timber the 

 square of the quarter-girth should be regarded as the sectional area 

 of the log or tree. 



Chapter II. 



On the measurement of yelled Trees. 



The felled trees should be cut up in the usual way, that is to 

 say, into logs and smaller pieces. 



1. Meanurement of Round Timber, 

 Several formulae have been devised for the determination of 

 the contents of round tiaber with more or less near approach to 

 accuracy, but only two are of practical utility. These are, 



(i) ^^—- — ' X I known as Smalian's formula: and 



(ii) ff,„^ kno'wn as Ruber's formula. 



