, depending on the direction _from_
which they come.

Imagine the firing point to be in the middle of the face of a clock
and the target to be at 12 o'clock; 3 o'clock will be on your right, 9
o'clock on your left, 6 o'clock in your rear and 12 in your front.

A wind blowing _from_ your right to your left is called a 3 o'clock
wind; one blowing _from_ your rear is called a 6 o'clock wind; one
from your front, 12 o'clock wind, etc.

[Illustration: Fig. 43]

The score-books issued by the Ordnance Department have windage charts
that have been carefully worked out and all you have to do is this:
Estimate the force of the wind in miles per hour, and determine the
direction from which it comes (whether a 9 o'clock wind, a 2 o'clock
wind, etc.). Then look at the windage chart and see just how much
windage you must take.

The simplest and best rule for the beginner is for him to make his
estimate and then ask an experienced shot what windage to use,
checking this up with what he found on the windage chart. In this way
he soon learns to estimate for himself.

Practice estimating the wind. Ask a man who has been making 5's and
4's what windage _he_ used and check up with your own estimate.

You can find out the direction of the wind by watching smoke, grass or
the limbs of trees.

Throw up some small straws and watch which way they are blown, or wet
your finger and hold it up. The wind cools the side it strikes.

A 12 o'clock wind slows up the bullet and a 6 o'clock wind helps it
along,--so, in the first case you would need more elevation and in the
second less elevation.

=1392. The zero of a rifle.= The twist of the bullet given by the
rifling of the barrel causes the bullet to move to right, which
movement, called "the drift," is compensated by having the slot in the
rear sight for the drift slide, slope to the left. However, in some
rifles the compensation is too great and in others it is not enough.

That reading of the wind gauge necessary to overcome the drift of a
rifle at a particular range is called the "zero" of that rifle for
that range, and all allowances for wind should be calculated from this
reading.

The "zero" of a rifle is found by shooting it on a perfectly calm day.

=1393. Estimating distance.= Ability to estimate distances correctly
is an important part of a soldier's education.

While it is true that fire on the battlefield will usually be by
groups and the ranges will be given by officer