  One of the most beautiful notions of metric geometry is the Gromov-Hausdorff
distance which measures the difference between two metric spaces. To define the
distance, let us isometrically embed these spaces into various metric spaces
and measure the Hausdorff distance between their images. The best matching
corresponds to the least Hausdorff distance. The idea to compare metric spaces
in such a way was described in M.Gromov publications dating back to 1981. It
was shown that this distance being restricted to isometry classes of compact
metric spaces forms a metric which is now called Gromov-Hausdorff metric.
However, whether M.Gromov was the first who introduced this metric? It turns
out that 6 years before these Gromov's works, in 1975, another mathematician,
namely, David Edwards published a paper in which he defined this metric in
another way. Also, Edwards found and proved the basic properties of the
distance. It seems unfair that almost no one mentions this Edwards's paper
including well-known specialists in metric geometry. The main goal of the
present publication is to fill this gap.
