Complete set of all two coastal profiles of China that appears in the rare Part VI of the Zee-Fakkel only. Depicted are all the coasts as observed from the water, the profiles are an essential tool to determine the exact location of the ship.

Shown are the coastal profiles between Macao and Quemoy (Kinmen), including the islands of Lantaon, where Hong Kong would be founded nearly a century later.

"The development [ of the van Keulen atlases ] culminated in the publication of Part VI: the famous pilot-guide for the East Indies."

(Koeman).

"The sixth part of the 'Zee-Fakkel' holds an exceptional position among the atlases published by the House Van Keulen. It contains the desciptions and the charts pertaining to the navigation in East Asian waters, a region where the Dutch held a prominant and envied position; this required a certain secrecy in matters of charts and sailing instructions for the pilots. In the sixt part of the 'Zee-Fakkel', published in 1753, these instructions and charts were given in print for the first time.

Long before 1753, detailed information on the coasts and waters in Asia and the Maleisian Archipelago was only distributed in manuscript form to the pilots of the merchant vessels which sailed from Amsterdam. This information was embodied in the so-called 'Secret atlas of the V.O.C.' (Verenigde Oostindische Compagnie = United East India Company). The charts were kept in the East India Housein Amsterdam under custody of the Hydrographer of the V.O.C. [...].

Several of the charts in the sixth part of the 'Zee-Fakkel' were engraved after the Ms. master-models in the archives of the V.O.C. [...].

During the period 1726-1755, when Johannes van Keulen II was in office as Hydrographer of the V.O.C., the first charts for the navigation to the East Indies and in the Malasian Archipelago were engraved. [...] They mark the beginning of what was to become the pilot guide for the East Indies. Gradually, when a policy of secrecy was no longer of use because English and
French charts of Asian waters has already appeared in print, more Dutch charts were published. Finally, in 1753, Johannes van Keulen II issued the entire set, provided with a text by Jan de Marre. The splendor displayed in Part VI marks this volume as the most beautiful pilot guide ever published in Amsterdam. [...].

Immediately after 1753, Joh. van Keulen started revision of the work. He added new charts and a final edition with register and numbered plates appeared after his death, ca. 1757. But no edition is known with a date other than 1753 on the title page."

(Koeman).

The Dutch produced a remarkable number of enterprising and prolific map and chart makers but not even the Blaeu and Jansson establishments could rival the vigour of the van Keulen family whose business was founded in 1680 and continued under their name until 1823 and in other names until 1885 when it was from wound up and the stock dispersed at auction.

Throughout the history of the family, the widows several of the van Keulens played a major part, after their husbands' deaths, in maintaining the continuity of the business. The firm was founded by Johannes van Keulen who was registered as a bookseller in Amsterdam in 1678. In 1680 he published the first part of his 'Zee Atlas' which, over the years, was expanded to 5 volumes and continued in one form or another until 1734. More ambitious and with a far longer and more complicated life was his book of sea charts, the 'Zee-Fakkel', first published in 1681–82, which was still being printed round the year 1800. A major influence in the development of the firm was the acquisition in 1693 of the stock of a rival map publisher, Hendrik Doncker.

Although the firm was founded by Johannes van Keulen, he was primarily a publisher; it was his son, Gerard, a talented engraver, mathematician, Hydrographer to the East India Company, who became mainspring of the business which not only published charts but also books on every aspect of geograpy, navigation and nautical matters,

(Moreland and Bannister)

It was grandson Johannes van Keulen (II) who in 1753 produced Volume VI of the Zee-Fakkel for the VOC East Indiamen, containing printed charts for the navigation covering the waters from the Cape of Good Hope to Nagasaki . The atlas was not commercially sold and only for use on board of VOC ships, therefore it is also refered to as the 'secret atlas' odf the VOC. The engraving quality and craftmanship surpasses that of all earlier printed sea charts.

Sea charts from the secret atlas are among the rarest and most desirable sea charts for collectors.