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that almost any of the boundaries may serve as a base-line; I always 
use one surveyed by Government and clearly marked with stones so 
whatever may happen, as iong as the base-line is fixed the whole 
co-ordinate system may be reconstructed on it. 
'*In the attached plan I would chose X-Y as my base-line; as soon 
as it has been properly cleared, pegs are put in along it correctly 10 
chains apart, starting' at X. On the point marking the last 6th length 
of whole ro chains the right angle-line, Y-Z is put in, if possible with 
a theodolite; prismatic compasses are sometimes unreliable and as 
this is the one line which cannot be checked it is as well to take 
some trouble in getting it accurately at right angles to base-line. 
On this second line lengths of 10 chains are again marked and the 
rest is detail work which cannot only be easily done by any man 
conversant with a prismatic compass but which can also be easily 
checked and amended by taking and measuring frequent cross-shots 
to either base-line or right-angle-line, or to the last paraded line to 
these two which has been checked previously. 
The main difference between these two important lines is that 
from the base-lines all shots will have to go in one direction whereas 
from right-angle-line rentices start towards right and left. 
In laying out a block of jungle it is bf course essential that the 
crossing points of any two rentices indicating, as they do, one of the 
four corners of any 10-acre blocks, should be well marked. Pegs 
and posts, however big, are not safe as they can entirely disappear 
in felling and burning. I found a strong peg rammed flush with 
the ground and covered with 3-6 big stones to answer well, 
contractors having been asked not to fell trees across the rentices. 
In land where it is ha.d to get any stone I am having a strong peg 
put in the bottom of a 3 ft. x 3 ft. x 3 ft. hole. In flat land which 
has to be thoroughly drained I fancy that drains could advantageously 
be made to take the plr.ce of dividing rentices. 
It is, of course, by no means necessary to lay out the whole of a big 
estate in this way; in the attached sketch for instance, according to 
which it may be proposed to open a 100-acre field, all that is 
required is the "base line” and part of the “right-angle-Iine” ; 
further 20 chains each between A, B, C, D, E and F fields and 50 
chains each between fields 1 and 2, and 2 and 3. 
It will, however, be always useful to complete the whole system 
all over the Estate to begin with as opening work can then always 
be undertaken at the shortest notice and should at any time roads, 
watercourse, etc., have t6 be constructed through part of the jungle or 
works undertaken at any distance ftom the first clearing, the locality 
could be immediately located. 
It is of course essential that from the beginning a record of 
everything is taken, beginning with the two mainlines; that not only 
all measures taken should be entered on plan, all corner pegs marked 
and complete squares made clearly distinguishable, further that a 
note and distance should be taken of every stream, hill, ridge, path 
