  The emergence of quantum theory in the early decades of the twentieth century
was accompanied by a wide range of popular science books, all of which
presented in words and in images new scientific ideas about the structure of
the atom. The work of physicists such as Ernest Rutherford and Niels Bohr,
among others, was pivotal to the so-called planetary model of the atom, which,
still today, is used in popular accounts and in science textbooks. In an
attempt to add to our knowledge about the popular trajectory of the new atomic
physics, this paper examines one book in particular, coauthored by Danish
science writer Helge Holst and Dutch physicist and close collaborator of Niels
Bohr, Hendrik A. Kramers. Translated from Danish into four European languages,
the book not only presented contemporary ideas about the quantum atom, but also
went into rather lengthy discussions about unresolved problems. Moreover, the
book was quite explicit in identifying the quantum atom with the atom as
described by Bohr's theory. We argue that Kramers and Holst's book, along with
other atomic books, was a useful tool for physicists and science popularisers
as they grappled with the new quantum physics.
