COMPUTATION AND OFFICE WORK 
33 
that his E and W departures balance, hence he should be 
in line. The difference between northing and southing 
gives him the distance. He may then set a second post, 
add the distance to his previous chainage, and proceed with 
his survey. 
COMPUTED TRAVERSE 
!- 
Field Notes. 
From Traverse Tables. 
Bearing. 
Distance. 
Latitude. 
Departure. 
N. 
S. 
E. 
W. 
N. 50° E. 
12.0 chains 
7.71 
9.19 
N. 9° 30' E. 
20.0 
19.73 
3.30 
N. 40° W. 
9.0 
6.89 
5.78 
S. 80° W. 
6.81 
1.18 
6.71 
34.33 
1.18 
12.49 
12.49 
1.18 
Distance due north 
33.15 chains 
Balance 
When a closed survey is made, that is to say, when a sur¬ 
veyor starts and finishes at the same point, it is evident that 
its (+) and (—) departures should be equal, also its (+) 
and (—) latitudes. Owing to the errors unavoidable in 
survey work it is very seldom that they do so reckon up 
exactly. The amount by which the two ends fail to meet, 
whether plotted or reckoned, is the error of closure, and the 
percentage of error is the ratio of this distance to the total 
length of the survey. A certain percentage of this error, 
say 1 in 500 or 1 in 300, may be allowable in an ordinary 
woods survey. For plotting and for area, however, it may 
be desirable to distribute the error through the different 
courses, and this, when the traverse has been reckoned out, 
is readily done. The error in both latitude and departure 
is usually distributed to the different courses in proportion 
to the length of each, but if any course was more difficult of 
chainage than the others, it may be given extra weight in 
