SURVEYING. 
IV. Cf X C7 + ft : 
c7 X 7,o 
d ? X cd ; 
de X dy -f- en 
ef X ej + ip 
ip X fg 
fz X ig + z,/ : 
Z r X z " + r-zu : 
rs X r-ru 
^ X *- v 
V. h« x gh 
hk X h« ki 
k* X kl 
cd 
c\ 4- 
h x 
il X 
gi X «i + Jg 
yg x j/ 
VI. 
: 490 X 1570 = 759300 
- 730 X 55 zz 62900 
= 510 X 45 = 22950 
- 230 x 1010 = 232300, 
z 215 X 750 ~ 161250 
z 370 X 70 zz 25900 
z 230 X 200 = 46000 
z 300 X 270 zz 81000 
z 40 X 200 zz 8000 
_ 230 X 50 zz 11500 
)1421100 
7.1055 
.4220 
16.88 
zz 210 X 70 zz 14700 
zz 770 X 370 zz 284900 
z 140 x' 50 zz 7000 
zz 260 x 70 zz 18200 
zz 330 X 550 zz 181500 
zz 560 X 700 zz 392000 
zz 350 X 70 zz 24500 
) 922800 
4.614 
2.456 
18.24 
4- lh zz 750 X 700 zz 525000 
z 260 X 280 zz 72800 
210 X 520 zz 109200 
Respective Contents. 
acr. rds. per. 
Field I. 
II. 
III. 
IV. 
V. 
VI. 
2 26 
1 10 
3 21 
0 16 
2 18 
3 2 
Total 
33 1 13 
b ; 
EC 
~ 
300 
1600 
ih zz 
350 
Cl 

600 
19 = 
250 
C12 
Cm 
= 
710 
800 
wlO zz 
160 
C n 
— 
950 
n 2 zz 
370 
Co 
— 
1380 
o 14 zz 
580 
CA 
zz; 
1400 
The plan of the estate being obtained by 
these dimensions, other lines must now be 
drawn in each field, dividing it into such geo- 
metrical figures as will most readily give the 
content ; as in fig. 26. 
By dividing the fields as here directed, the 
content of each may be found as follows : 
HOME PADDOCK. Double areas. 
d X 
x + ft 
■ - e f + ~ 
gi X gh -j -it — 
il X Tk 4- Im zz 350 X 820 zz 287000 
l,n X In — 820 X 120 zz 98400 
Triangle 
Do. 
Trapezoid 
Triangle 
zz 1040 X 315 zz 
e f 
eg X -j , & - — 
zz 90 x 660 zz 59400 
) 1152800 
5.764 
3.056 
2 . 
Notwithstanding some land-measurers have 
adopted the foregoing method, of normal lines, 
for their mode of practice, in making plans of 
estates, yet the following (by. triangles, &c.) 
seems preferable; being less subject to error, 
and more facile in operation. 
Det us suppose that the small estate, fig. 25, 
was to be measured, by means of a general tri- 
angle, and necessary off sets ; the measurer be- 
ginning at A, and measuring towards B, from 
thence to C, and returning to A, making all ne- 
cessary off-sets as he goes on ; required the true 
plan, and the measure of each field ? 
From the following dimensions, to plan the 
estate : 
Az 
= 
250 
a 1 
= 
60 
IX 
— 
60 
Xz 
zzz 
60 
A b 
— 
500 
b 2 
zz: 
320 
A c 
— 
730 
r 3 
zz; 
70- 
Ad 
— 
810 
d.A 
— 
MO 
Ke 
— 
94Q 
e 5 
— 
100 
AB 
— 
1500 
B k 
zr: 
210 
Bo 
— 
250 
06 
zz; 
120 
Bf 
— 
320 
f 7 
— 
100 
% 
BA 
— 
390 
480. 
■? 8 
— 
70 
36400 
b zz 630 X 565 zz__ 355950 
C ZZ 270 X 565 -}-230 zz 217350 
d zz 140 x 230 zz 32200 
2)641900 
3.2095 
GARDEN. 
Trapezium e zz 680 X 250 -j- ISO zz 2)292400 
1.462 
RIVER MEAD. 
Triangle f (the lower 4 
irregular boundary ( _ lg6 - x 8G0= 1603900 
being reduced by ( 
the Rule, p.755, cel.H. q 
Triangle g — 160 X 115 zz 18400 
Trapezoid b zz 320 X 115 4“ “140 zz 177600 
Triangle i zz 1275 X 440 zz 561000 
Do. k zz 275 X HO =z 
60 X no 4- 100 
Trapezoid l 
Do. m 
Triangle n 
70 X 100 4- 65 
70 X 65 zz 
Respective Contents. 
30250 
8600 
11550 
4550 
2)2415850 
12.07925 
acr. 
rds. 
pei 
Home Paddock 
3.2095 
— 3 
0 
33 
Garden •- 
1.462 
zz 1 
1 
33 
River Mead 
12.07925 
zz 12 
0 
12 
Total - 
- 17 
2 
38 
THE PLANE TABLE. 
Land-measuring may, in some instances, be 
expedited b,y instruments which set off lines in 
their relative positions, and the angles of theit 
inclination one to another ; the most convenient 
instruments for these purposes, are the Plane- 
table and the Theodolite. 
The Plane, or Plain-table, is composed of a 
smooth rectangular board, commonly of about 
15 inches by 12 ; around which is a frame, that 
not only serves to keep the paper smooth on 
which the plan is to be drawn, but, being gradu- 
ated into degrees, answering to a central point 
in the board, the angular bearing of any two 
lines, issuing from the station where the instru- 
ment is placed, may readily be ascertained ; or 
the angle itself may be drawn on the paper. — 
A magnetic needle and compass-box is fixed to 
one side of the board, which serves to point out 
the bearing of any line to the magnetic meri- 
dian. — There is, also, a brass index-rule, having 
sundry scales thereon, and also perpendicular 
sights at the end used herewith. The whole is 
supported on a three-legged stand, &c. move- 
able on a brass ball and socket. 
A land-measurer having planted his Plane- 
table at A, one of the inner angles of the field 
ABCDE, fig. 27, and from any assumed point 
on the paper (which may be considered as his 
station-point on the land) directed his sight 
along the boundary to B, and also to C, to D, 
105° O' 
59 30 
129 O 
66 30 
480 
550 
665 
730, he will 
' . 757 
and to E ; and, by measuring these lines on the 
ground, finding them to be as ff ov ' - 
AB zz 665, AC 885, AD 1030, apt. Ah 5 > d , 
he- may make a correct plan of the hel ‘ 
from thence, by drawing other hues on the plan, 
as heretofore directed, he may calculate the con 
tent thereof. . 
If the other sides of the same field, viz. bC, 
CD, and DE, &c. (fig. 27), had been measured, 
cither on the ground, or on the plot, the con- 
tent may be found by Rule 2. for the triangle. 
A measurer may take his observations from a 
point about the middle of a field, as at A, (ng. 
28,) and lake his angles of bearing to all the 
corners of the field, and measure the links to 
each corner, and from thence find the^content, 
for, suppose the Z. BAG 
A CAD 
Z. DAE 
A EAB 
And that the line AB 
AC 
AD 
AE — • ^ . . 
have two sides of each triangle, and then- in- 
cluded angle, given from whence lie may ma ' e 
his plan ; and by Rule 3. of triangles, had the 
content. . . ,, , , 
A measurer may take two stations in a neia, 
as at A and B, (fig. 29, the distance between 
which must be carefully measured) ; he must 
then from each station direct his sight to tu. 
corner of the field, and draw dotted lines ti 
they intersect each other. From the intei sec- 
tions of these dotted lines he must draw the 
boundary lines to make his plan ; in which ie 
must draw such measuring-lines as are nece&sary 
to find the content by the scale. 
A measurer may take four or more stations in 
a field, as abeg, (fig. 30,) and set up suen per- 
pendiculars as are necessary lor pertecting 1 ie 
boundary Imdfbi , ; the plan being laid down, the 
content of the field may be touud by scaling. 
THE THEODOLITE. 
The Theodolite is a circular instrument made 
of brass, graduated into degrees, &c. on which 
is an index-limb for taking horizontal ang es, 
surmounted with an arch for vertical aligns, 
and a telescopic sight. It has, usually, spirit- 
levels to adjust it by; and a compass, for an- 
gular bearings, checking the observations by 
the limb : the whole placed on three legs, and a 
ball and socket, or half-ball, and parallel plates, 
to set it level. , 
In all cases of land-measuring, where angles 
are required to be taken, whether horizontal or 
vertical, no instrument is so well adapted thereto 
as the theodolite ; its accuracy and dispatcti. 
far exceeding all other instruments used for that 
purpose, especially on large estates, where va- 
rieties of boundary, as well as inequality oi sur- 
face, are met with. 
In a single piece of land, the angular obser- 
vations may all be made from one spot in a 
field. . . . 
In this case, the theodolite being set at the 
station A, fig. 31, and properly adjusted (as 
hereafter described), the first observation to the 
picket-staff - at a, was zz 62° 20', from the north 
towards the east, and the length of the line A a 
zz. 660 links. 
The second observation, to b, between the 
south and east, zz 152° 0 ; , and the length of the 
line A b zz 960 links. 
The third, to c, between the south and. the- 
west, zz 200° O', the length 730. 
And the fourth observation, to d, from the 
north towards the west, 329° 5&, and the length 
599. 
From hence; with the help of a protractor, 
the plan may be drawn. 
It is evident, that if from the observation b, 
