Rectangular Coordinates of Rich Clusters of Galaxies on the Palomar Sky Survey Charts

Rectangular coordinates of the 2712 rich clusters listed in Abell's catalog have been calculated that allow quick identifications to be made on the charts of the National Geographic-PaThmar Obserz'atory Sky Survey. Right ascensions and declinations are given for epoch 1950 to facilitate the identification of Abell clusters with radio sources and clusters listed in other references.