regularly situated, put it
down where the pelorus is, and took a bearing from it of any object
desired.

In taking a bearing by pelorus, two facts must be kept in mind. First,
that when the bearing is taken, the exact heading, as shown by the
ship's compass, is the heading shown by the pelorus. In other words, if
the ship is heading NW, the pelorus must be set with the NW point on the
lubber line when the bearing is taken of any object. Second, it must be
remembered that the bearing of any object obtained from the pelorus is
the bearing _by compass_. To get the true bearing of the same object you
must make the proper corrections for Variation and Deviation. This can
be compensated for by setting the glass dial at a point to the right or
left of the compass heading to correspond with the compass error; then
the bearing of any object will be the true bearing. But naturally, you
will not be able to make compensation for these errors unless you have
immediately before found the correct amount of the compass error.

_Parallel Rulers_

The parallel rulers need no explanation except for the way in which they
are used on a chart. Supposing, for instance, you wish to steam from
Pelham Bay to the red buoy off the westerly end of Great Captain's
Island. Take your chart, mark by a pencil point the place left and the
place to go to and draw a straight line intersecting these two points.
Now place the parallel rulers along that line and slide them over until
the nearest edge intersects the center of the compass rose at the bottom
or side of the chart. Look along the ruler's edge to find where it cuts
the circumference of the compass rose. That point on the compass rose
will be the _true_ compass course, and can be expressed in either the
new or old compass, as, for instance, 60 deg. or N 60 deg. E. Remember, however,
that this is the _true_ course. In order to change it into the compass
course of your ship, you must make the proper corrections for the
compass error, i.e., Variation and Deviation and for Leeway, if any.

_The Lead and Sounding Machine_

The lead, as you know, is used to ascertain the depth of the water and,
when necessary, the character of the bottom. There are two kinds of
leads: the hand lead and deep-sea lead. The first weighs from 7 to 14
pounds and has markings to 25 fathoms. The second weighs from 30 to 100
pounds and is used in depths up to and over 100 fathoms. Put in your
Note-Book:

Fathoms which