THE TRANSIT 
85 
Notes may be kept as follows: 
Line 
Azimuth 
Bearing 
Distance 
A —B 
162° 
12' 30" 
N. 17° 45' W. 
6.40 ch. 
B—C 
223° 
30' 
N. 43° 30' E. 
7.25 ch. 
C —D 
280° 
25' 
S. 79° 30' E. 
4.92 ch. 
D—E 
5° 
43' 30" 
S. 5° 45' W. 
6.10 ch. 
Caution. In transit surveying, where angles are read, 
each line is referred to the one that goes before, and in 
consequence an error in reading one angle is perpetuated 
throughout the survey. Further than that, some of the 
errors arising from lack of adjustment of the instrument 
are multiplying errors, increasing as the work proceeds, 
and unless every precaution is taken they may, though 
individually small, mount up to a very considerable size 
in the course of a survey. 
With compass surveying, on the other hand, though 
bearings cannot be read with great exactness and single 
angles are not so accurately determined as with the transit, 
yet errors have not the same opportunity to accumulate 
because each course in the survey is referred anew to the 
meridian. 
The man who is not in constant practice, therefore, will 
be likely to find that he attains better results with the 
needle than by turning angles, and in that case, unless the 
telescope is wanted for stadia measurements, the compass 
is the instrument to use. The matter of cost is, in woods 
conditions, strongly on the side of the compass, for it is 
usually expensive to cut away for the long, clear sights 
requisite to the running of a reliable transit line. 
Typical examples of stadia surveys such as the woods¬ 
man may have occasion to perform are as follows: 
Stadia Survey of a Pond as carried out on the ice. 
The needle was relied on in this case, but it will readily be 
understood that angles might be read instead of bearings 
and the survey so rendered independent of the magnetic 
needle. If the survey were to be made in summer, points 
