  The discovery of cosmic rays, a milestone in science, was based on the work
by scientists in Europe and the New World and took place during a period
characterised by nationalism and lack of communication. Many scientists that
took part in this research a century ago were intrigued by the penetrating
radiation and tried to understand the origin of it. Several important
contributions to the discovery of the origin of cosmic rays have been
forgotten; historical, political and personal facts might have contributed to
their substantial disappearance from the history of science.
