On April 20, 1697, an advertisement appeared in the Amsterdamsche Courant for a new product: the zak-aardebol, or pocket globe. This globe was no more than two inches (five cm.) in diameter and was encased in a leather cover on the inside of which was presented the heavens with constellations – one of the earliest geocentric representations of celestial space. The producers of this pocket globe, the mapmakers Abraham van Ceulen and Gerrit Drogenham, recommended their new product as “Very appropriate for all devotees of astronomy and other sciences, as well as [all those] who would customarily carry a pocket watch with them.”

The pocket watch was then a recent development of the clockmaking industry, which had extended its markets from church towers and other public structures to private homes with the invention by Christiaan Huygens of the pendulum clock in 1657. Its diffusion through bourgeois and even middling and farm families was remarkably rapid, and the new pocket watches, adding mobility to the science of time keeping, met with a very positive reception among those who could afford the steep price. Van Ceulen and Drogenham presented their pocket globe as the logical companion to the pocket watch – something that the well-equipped modern man would find essential. The owner of both instruments would always know where he or she was – both in time and in space. The appeal will not be lost on those who move about today with mobile phones and BlackBerrys always on their person.