An exceptional pair of Terrestrial and Celestial Globes

Gerard and Leonard Valk: famous 18th-century globe makers
In the recently published book Globes in Nederland, de Wereld in het klein (Globes in the Netherlands, the World on a Small Scale) by Diederick Wildeman published by Walburg Pers calls the period during which the Valk family was at work The era of the Valks. Gerard Valk, a citizen of Amsterdam, was a publisher and engraver. He and his son Leonard became the most important globe makers of their time. The engraving work in particular was renowned for its superior quality. The first examples of Gerard Valk's terrestrial globes show an image of the world that was outdated. California, for instance, is pictured as an island and the coasts of Australia, New Guinea and New Zealand are missing. The terrestrial globe was based on Cassii's dated 1698 while the celestial globe used Hevelius's Uranographia of 1690 as an example. The second state - ours - was adjusted and has a revised map of the world drawn by
Leonard Valk, who worked with his father from 1711 to 1726. Leonard died in 1746, but that did not signal the end of the globe-making firm: his widow continued the business with her brother Petrus and his son. They did not make any new globes but sold off the old stock. At the end of the 18th century they had had enough and sold the globe business to the publishers Mortier, Covens & Zoon.

The making of globes
Before 1680 there was actually no written manual for making globes. The skill was learned in practice. The most difficult part was the spherical form. A semi-spherical mould made of wood or metal was coated in fat or oil and then covered with many layers of papier-mâché. The trick was to keep the outer surface as smooth as possible. When both halves were ready, a wooden axis was fitted and the halves were brought together. The sphere now had its definitive shape and a final layer of plaster ensured the required smooth surface to which the segments of the chart were applied. This latter was extremely painstaking and time- consuming work because the long strips of the chart had to fit together to the nearest millimetre. Once the chart had been entirely or partially coloured, a layer of varnish was applied by way of protection. The meridian ring around the globe was supported by a single central column.