i DENDROMETER, 
forms i fame angle with the wil as the bough forms 
_with the body, or trunk, of t This may be 
of any convenient length, divided ae a -parts of the 
fame feale with all the foregoing divifions 
t the extremity of the fixed axis, on a centre, an in- 
dex, R, with telefcopie fights, = horizontally upon the 
moveable limb of the fliding pi this horizontal 
index, R, may be fixed a fimll ani, iT, defcribed with 
any convenient radius from t 
moves, and divided into 90°; 
equal ee i difere ved c 
jeQts, above the plane of the pest and whofe hale i is the 
neareft diftance pede the perpendiculars, in which thofe 
objects are fituated. The dendrometer is fitted to a fests 
lite, and may be ufed either with or without it, as occafion 
requires. 
“¢ The principal ufe of this inftrument is for meafuring the 
it refts, or of any figure, whether regular or irre- 
gular, and alfo the length and diameter of the boughs, by 
mere in{pe&tion ; and the inventors of it have calculated ta- 
bles, annexed to their account of the inftrument itfelf, by the 
help of which the quantity of timber in any tree is obtained 
me out calculation, or the ufe of the fliding rule. 
‘“* The inftrument is reCtified by fetting it in a perpendicu- 
lar sonra: ae means of the plummet, and {crewing it to 
the ftaff; then the altimeter is placed in the exa&t pofition 
of the bee, whether perpendicular, reclining, or inclining, 
and is fcrewed fat. If the tree ftands on level ground, the 
horizontal diftance from the tree to the axis of the inftru- 
ment is meafured with a tape line, and. the radius is moved 
with the key, till that diftance be cut upon it by the infide 
of the diameter: but if the ground be flanting, the diftance 
from the tree to the inftrument i i3 aaa an nd the eleva- 
X e 
the ho any line by 
infide of the di 
the tree, the elevation index is firft m 
the bottom of the tree, cut by the horizontal wires, is ob- 
ferved meee the fights, and the feet and inches marked 
b ex upon the altimeter below the point of fight, 
yt 
or horizon ta ne _ note ge own: 
efore cut by the infide 
e tape-line, in taking the dif- 
ied . the centre of the bod of the 
tree; then the ceo index is lowered to that part of the 
tree, of which the diameter is to be taken, and is {crewed 
8 
faft. Set the moveable limb of the fliding-piece quite fraight; 
and the edge of the horizontal index upon the firft divifion 
of it. Turn the whole inftrument about to the left hand, 
till you fee, through the fights, the left fide of the tree cut 
exactly by the perpendicular wires; then the inftrument be- 
ing fixed, move the fights only upon the eee piece, till 
you fee the right fide of the tree, cut allo © perpendicus 
lar shale and you will yy the true een eee by the 
nZo index upon the fliding-piece, which is to be ens 
tered ina ou in& as of the field-book. 
“ For the boughs: let the diftance on the radius be now 
reduced to its former quantity, and the elevation index 
moved upwards, till the bough is feen arcueh the fights, 
and {crewed faft. Set the moveable part of the fliding 
piece ina pofition gia to the bough, a the edge - 
the horizontal index he firft divifion of i 
whole Parole cee sil you fee, through he fights, ie 
fhoot of the bough, -— to the trunk cut by the perpendi- 
cular_wires ; a we the fights, till you fee the other 
end of the bough ue i the faid wires, and note the feet and 
inches marked by the horizontal index on the moveable limb 
of the fliding piece, which wiil give the yeas length of the 
pough to be inferted in the field-book. And the girth of 
the bough may be obtained, by diredting ‘the fights to that 
S 
after which Jet the elevation index be moved upwards, till the 
upper fide of the bough, cut by the horizontal wires, is feen; 
the feet and inches marked upon the altimeter are to be noted 
s before: the er quantity fubtraéted from the latter, 
will give the true te ter of the bough, a is entered 1 
he field-bo true folidity, both o y of the 
tree, and of the Met may be found from a diameter and 
ode i tables calculated for this purpofe. 
ter, fitted to a theodolite, may be applied 
to ae ieee of heights s and diftances of obj<-¢ts accefli- 
ble or inacceffible, whether fituated in planes parallel, or ob- 
lique, lich inftrum It 
ay be alfo ufed for taking all angles, whether vertical, ho- 
rizontal, or ob any pofition of t in which 
they are formed ; and thus for facilitating the pra€tical ope- 
rations of engineering, land-furveying, level'ing, mining, &c. 
and for performing the various cafes of plane trigonometry, 
Lda calculation; of which the inventors have fubjoined 
ariety of examples to ara a of the inftrument in 
ete eben upon the Den 
No anding the otenfble extenfive application of 
this aaa t, it does not appear that the ufe of it has been 
generally adopted, which may ie principally attributed to. 
its complicated conftruction 
th volume of the TranfaGtions of the Society for 
the encouragement of Arts, Manufadtures, and Commerce, 
t whic 
James Broad, gives the name of Gay Meafi ure for Ti 
which in fa@ isa ye eile Aae in he trict fenfe Of 
the word, and it therefore deferves a place i in the prefent ar- 
ticle. 7 inftrument is reprefented in Plate IIL. Surveyings. 
, 2a; Mr, Broad f. 
ede are two long pieces of well. 
