Abrams SC-1, Техническое руководство

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MAINTENANCE MANUAL
meridian)
according to the indicated sign,
plus
or minus,
to
obtain apparent or true sun time.
Each
number
is directly
opposite
one end
of
a
heavy line.
The
lines are opposite the
date lines which represent the date to which the correction
is
applied. Intermediate values are obtained by adjustment
within
the length
of
the line.
For
a
part
of the months
of
De
cember
and
January,
the equation factors are given separately
opposite
the
appropriate
date.
The date bar
is
made
for
the
year
1943;
however, the equation
of
time
factors
do not vary
more than
a
few
seconds
from year
to
year.
e.
Solar Plate.
—
The solar plate (item
5)
is
an oval-shaped
plate mounted
so
that
it will
slide on the date bar.
It
has
marked on
its
surface
a
series
of
elipses,
one
for
each
third
degree
of latitude starting
at the equator and
running
each
way
to the
north
and south
45th
latitude
lines. These are crossed
by a
series
of hyperbolas which represent local apparent time
(true
sun time)
from
6 a.
m.
to
6
p. m. by
quarter hour inter
vals.
The
order
of
the hour numbers
is
reversed
in
the north
and south latitudes.
The
solar plate indicates where to
set
the
shadow bar
for any given time-latitude setting.
FIOUBE
3
—
The Solar Plate.
4