A Visual Atlas of Double Stars Volume 1 and 2 by Mike Ropelewski
The study of double stars was in its heyday during the eighteenth and nineteenth centuries. Telescopic observations of the night sky revealed that many stars were members of either double or multiple groupings and it became clear that chance alignment could not alone account for the large number of these objects which were being discovered. In 1803, the eminent British astronomer William Hershel presented definite proof that, in many cases, the components of double stars were gravitationally connected. It was the culmination of many years' work and led the way to further scientific observations of binary stars.