Milford chronicle., 1915-07-16
(Continued from lagt week.l

These are very easily learned. The
character of streams is indicated on the
) map by the use of the proper abbrevia-
: tions given in the list above. For in
stance, a stream fifteen feet wide and ten
, feet deep, that could not be forded, would
} be indicated by drawing a line showing
its course and then writing along this
line '15 wd x10, d. n. f." The mean
ing of II. f., of course, is not fordable.
Bridges are shown by the use of the
proper conventional sign and the charac-
ter and span indicated by abbreviations.
For instance W. K. p, written alongside
of the conventional bridge sign, means
wooden king post bridge. The length,
width and height above the water are
indicated by drawing a line and writing
the length and width above it and the |
height above water below it.
Those of you who do not know what |
king post or queen post structure is should |
look up these terms at once in the die
tiOnary, read the description and study
the illustrations so that you will know
them when seen.
Location on the map of the different
principal landmarks, etc. Suppose you
are starting to draw a map of the coun
try along a certain road. Off to the left
is high hill. You want to put it on
your map. How are you to determine
its exact location without elaborate sur
veying instruments? First draw your
north and south line as explained in the
last lesson. Then carefully place your
ruler on the paper so that it will be in ex-
actly the direction of the road. Sight
along it to be sure it is accurately placed
and then draw an indefinite line along
the ruler. Mark the spot where you are
standing. Now place one end of the
ruler at this point on the line, and using
this end as a pivot, move the ruler so
that when you sight it, it will be in an a
exact line from where you are standing =
10 the top of the hill, being careful of :
course to keep the line on the map rep a
the road precisely parallel to =
he actual road Now draw line along
he ruler in this position. Go down the l.,
Dad counting your strides as you go un- !.
il you reach a spot, say about quarter n
If a mile away, suitable for another OBJ =
ervation of the hill top. Put your scale
N your map and mark your exact loca- -
ion on the road. Now take your ruler -
nd make another fighting at the hill Il,
Op from this second position, and draw =,
line along it. These two lines will in stt
ersect of course, and the point where -,
hey cross will show the exact location ~
the hill top on your map. This method {,
called Intersection. Its accuracy
epends on the care with which you pace =,
f and mark on the map the base line,
lat is, the distance between the two
oints from which you sight at the OBJ
ct. When this is done carefully, it is a /
accurate method.
When sighting be sure that the north =.
a. 90 10 - L. ~
lie north and south line as shown by 80
,ur compass. Everything on your map r. "a
zen will be in the proper relative posi- SS;
ons to each other and your sightings ''-i
i'll be correct. The opposite to Inter -,
ction is Resection and is method used 81;
map reading. You want to locate IL
ur exact position on a map. Off to the d,,
# is a house on hill, and in another of
rection a water tower. You find where ,
ese two points are indicated on the -,
lp. See that the north and south line a.
the map agree with your compass, and \
en- place a ruler on your map touching -
e spot indicating the house on the hill, e..
d sight along it until it is in a line
tn the actual house on the hill and -.
aw a line along it. Then place the -,
Ter in a similar way on the water tower
the map and sight at the actual water -
yer and draw that line. The two lines d.
u cross each other, and the point of ''ie
,ssing will mark your exact location on
: map. The methods of locating OBJ
is have now been explained and it
" remains to take up the methods of
presenting distances up ard down, that MIL
7ertical distances or elevations. 1t is
sufficient to merely indicate the top
a hill on a map.
We must show how high the hill is, 1t
whether the slope is a steep one or true
radual one, which side is the steepest, T
The method of doing this is called F
touring. Imagine a hill, perfectly H
nd at the base and sloping evenly on P
sides up to the top, making a perfect peol
e. Say it is 100 feet high. Now say j.
we draw a line around its base, and nue.
d draw another line around it at a bacl
1t 20 feet higher, this is 20 feet higher hart
not 20 feet along the slope, which of of
-se, will be considerably greater. Doa
tinue drawing these lines around the bic
at points 20 feet of elevation apart hav,
hill being 100 feet high, there will PI
TX of these circles, the one at the top ply {
purse being only dot. Now imag- Kidr
yau are up in a balloon, directly had.
e the top of a.hill. Look down and falo,