127 
HEIGHT OF A TREE. CONTENTS OF A LOG. 
MEASUREMENT OF TREES 
AND LOGS. 
HEIGHT OF A TREE. 
on scTen e ce helg Esse^Nl taU tr6e Can be kn0wn onl y some method based 
angles and f ! l f a PP llances are an instrument for accurately registering 
g es ana a tape for measuring a base or ground-line The anode mn«5 
convenient for ordinary use is 45“ With instrument set to this, sight Tex 
o ice. Place mark on ground exactly below instrument. Measure distance 
along ground between tree and mark. Add height of instrument so as to extend 
base to point where angle of 45“ touches the ground. If tree k krge add “so 
a f diametei of stump. Assuming that the ground is level and the tree perpen¬ 
dicular, the base or ground-line will then equal height of tree. By setting 1 instru 
men level ,„y rive Ml i» ™ md „.y be detect »d aJ&SgSSi 
mgi>. Othei angles require that the base shall he multiplied or divided These 
hree areconvenient :-60“ with base multiplied by 1.732; G3j“ with base multiplied 
by 2; 26 s with base divided by 2. A surveyor with theodolite can use any angle. 
ie amateur is restricted. An Abney Level is a very convenient instrument for 
general use. 
CONTENTS OF A LOG. 
It is usual in New Zealand to express contents of a log in terms of the super¬ 
ficial foot, which means a piece of hoard one foot square and an inch in thickness. 
Girth of a log is taken midway between the ends, after chipping off a ring of bark. 
Where the girth contains even feet or extra inches easily convertible into decimals 
of the foot, as 3, 6, and 9, proceed as follows:—Multiply girth into itself; multiply 
product by 3; divide product by 4; multiply quotient by length of log in feet. 
(a) Log 8' x 16' (girth and length). 
(b) Log 
8 
9.5 
8 
9.5 
64 
475 
3 
855 
4)192 
90.25 
3 
48 
16 
4)270.75 
288 
67.6875 
48 
20 
768 super, ft. 
1353.7500 
Read as 1354 super, ft. 
A.A 
