Austral Pole.
The north pole of the magnet is thus called sometimes in France; the
austral pole of a magnet is the one which points towards the north polar
regions As unlike magnetic poles attract each other, it is but rational
to call the north-seeking pole of the magnet the south or Austral Pole.
In the same nomenclature the south pole of a magnet, or the
south-seeking pole, is called the Boreal Pole.
A. W. G.
Abbreviation for American Wire Gauge, q. v.
Axis, Electric.
The electric axis of a pyroelectric crystal, such as a tourmaline
crystal; the line connecting the points of greatest pyroelectric
excitability.
Axis of Abscissa.
In a system of rectilinear, or right angle co-ordinates, the horizontal
axis. (See Co-ordinates.)
Synonym--Axis of X.
Axis of Ordinates.
In a system of rectilinear right angle co-ordinates, the vertical axis.
(See Co-ordinates.)
Synonym--Axis of Y.
Azimuth.
The angle between the plane of the meridian and the plane of an azimuth
circle, q. v.
Azimuth Circle.
A great circle, whose plane passes through the zenith or point of the
heavens directly overhead; any great circle in whose plane the vertical
at the point of observation is included.
Each celestial body has or determines an azimuth circle.