  In this work, we present a new interpretation of the only static vacuum
solution of Einstein's field equations with planar symmetry, the Taub solution.
This solution is a member of the $AIII$ class of metrics, along with the type D
Kasner solution. Various interpretations of these solutions have been put
forward previously in the literature, however, some of these interpretations
have suspect features and are not generally considered physical. Using a simple
mathematical analysis, we show that a novel interpretation of the Taub solution
is possible and that it naturally emerges from the radial, near-singularity
limit of negative-mass Schwarzschild spacetime. A new, more transparent
derivation is also given showing that the type D Kasner metric can be
interpreted as a region of spacetime deep within a positive-mass Schwarzschild
black hole. The dual nature of this class of $A$-metrics is thereby
demonstrated.
