1777 DE VRIES, K. - Schat-Kamer ofte konst der stuurlieden, behelzende een duidelyke onderwyzinge in de navigatie. . . [bound with] Tafelen bevattende De Sinussum, tangenten en Secanten. . . [bound with] Geographische Tadfel...

Schat-Kamer ofte konst der stuurlieden, behelzende een duidelyke onderwyzinge in de navigatie. . . [bound with] Tafelen bevattende De Sinussum, tangenten en Secanten. . . [bound with] Geographische Tadfel vande Graaden.. Voornaamste Zee-haavens. .

Rare and important manual originally prepared by Klaas de Vries including "Schat-Kamer ofte konst der stuurlieden" (Treasure-room of the art of Navigation) and published by Johannes van Keulen [bound with] Tafelen bevattende De Sinussum, tangenten en Secanten. . . [bound with] Geographische Tafel vande Graaden. . . Voornaamste Zee-haavens. ..

In 1702 appeared with the Amsterdam publisher Johannes Loots a handbook about the art of navigation which proved to be very popular and during the century more than once was issued.

It was the "Schat-Kamer ofte konst der stuurlieden" (Treasure-room of the Art of Navigation) by the Amsterdam teacher in mathematics Klaas de Vries. The book gives a clear picture of several aspects of maritime navigation.

An important issue in the "Treasure-room" is the height measurement of the sun or a star above the horizon, in order to calculate the latitude, as well as how to calculate the meridian.

De Vries mentioned that on board celestial globes were used and he described the three by Dutch sailors most common used instruments for height measurement. He considered the "graadstok" or "Jacobsstaf" (Cross-staff) as the most important, the other were the "Davis quadrant" and the "spiegelboog" (Mirror-staff). The latter was in 1660 invented by Joost van Breen, a ship provisions-master of the VOC chamber Zeeland.
De Vries described the Cross-staff the most comprehensive and explained how the sailor could make one him selves (pp.286-293).

He discussed the "apparent" altitude of a celestial body above the horizon and the necessary corrections to be implemented to calculate the "true" height and he therefore provided the necessary tables.
The "Treasure-room" explained how to calculate the times of high and low water. Knowledge important for departure and arrival at ports.
Navigational guidance, such as meridians, "breedteparallellen", the equator and the tropics, were explained by De Vries. He discussed the compass, compass needles and the variation, application of which was important for safe navigation.

The Treasure-room described how the length of a day and night and the times of rise and fall of the sun were calculated.
For this 1777 edition the wind directions for the route between the Netherlands and Java has been replaced by "triangle measurement ".<
A topic that got special attention was the actual position finding on a "platte en de wassende kaart" (Mercator projection chart) done by measuring the distance traveled in nautical miles. The distance was noted in a "handlog" and the speed of the vessel was measured regularly. The log consisted of a buttons labeled long line, rolled on a reel, and at the end a triangular shelf with some lead. One threw the plank at the stern into the sea where it floated and the mate counted with the aid of a hourglass for fifteen seconds, the number of passing nodes. That number corresponded to the speed in miles per hour.

The Treasure-room contained a large number of examples of the various types of calculations and included many sinus, tangent and secant tables by Bernardus Joannes Douwes.

The Treasure-Room contained a large number of examples of various types of calculations. These were training issues were the prospective mate could improve skills and test his knowledge.

On ocean routes however the knowledge of sea currents, and prevailing and seasonal winds remained knowledge based on experience of generation to generation which was passed by the sailor. The "Schat-Kamer" however offered the Dutch sailor the basis of maritime navigation for more than a century.

At the end we find a 40 page listing "Geographische Tafel van de graaden dere breedte en poolshoogte en lengte of middagscirkel, van de Meest Bekende Steeden, rivieren, caapen, Baayen. En inzonderheid der voornaamste Zee-Havens des Aardryks.
Of Korean interest is page 12, with "Corea, op de Zuid-Kust van China. Latitude 34-50 N. Longitude 142-22".

Interesting reading : http://www.knaw.nl/Content/Internet_KNAW/publicaties/pdf/20031017.pdf