Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the idea that reality can be modeled in ways that communicate spatial information effectively. The Dutch were famous for it, and obsessed with it.

How did the sailors of early modern Europe learn to traverse the world’s seas? By going to school and doing math problems...

In the 17th century the Dutch had no choice but to figure out new methods of navigating across the open water. Instead of memorizing the shoreline, they looked to the heavens, calculating time and position from the sun and the stars.

Celestial navigation was certainly feasible, but it required real technical skills as well as fairly advanced mathematics. Sailors needed to calculate the angle of a star’s elevation using a cross-staff or quadrant. They needed to track the direction of their ship’s course relative to magnetic north. Trigonometry and logarithms offered the best way to make these essential measurements: for these, a sailor needed to be adept at using dense numerical tables. All of a sudden, a navigator’s main skill wasn’t his memory – it was his mathematical ability.

To help the average sailor with these technical computations, maritime administrators and entrepreneurs opened schools in capital cities and port towns across Europe. Some were less formal arrangements, where small groups of men gathered in the teacher’s home, paying for a series of classes over the course of a winter when they were on shore.

Van den Broucke taught readers and students a useful technique: how to use the Little Dipper to tell time. The handle of the dipper points at the North Star, and the bowl of the dipper rotates around it over the course of 24 hours. That means that when the two farthest ‘guard stars’ moved 15 degrees, one hour has passed. Once the constellation has rotated 90 degrees, six hours have passed. This functionality was so useful that most early textbooks included diagrams, often with volvelles, moveable discs that help the reader understand the concept.

By the time Gietermaker published the Golden Light of Navigation half a century after Van den Broucke’s Instruction, nautical manuals had evolved. The definitions that had been so important – pole and equator, zenith and meridian – had become common knowledge, and sailors now focused on a different set of essential skills: addition and subtraction, multiplication and division.

Fortunately, in the 17th and 18th centuries, practical mathematics took off. For a reasonable fee, anyone who wished could acquire this bookish knowledge.

Early modern navigation students memorized definitions and took notes but also got their hands on instruments, and answered many, many practice questions. Zodiac songs, creative diagrams, hands-on lessons along the beach – this combination of memory and mathematics caught the imagination of mariners, making it easier to grasp the technical skills needed on the high seas. Far from being drunken sailors, these men were clever mathematicians, using traditional approaches alongside the latest technologies to reach the far side of the globe.

As Dutch ships reached into the unknown corners of the globe, Dutch cartographers incorporated new discoveries into their work. Instead of using the information themselves secretly, they published it, so the maps multiplied freely. For almost 200 years, the Dutch dominated world trade. Dutch ships carried goods, but they also opened up opportunities for the exchange of knowledge. The commercial networks of Dutch transnational companies, e.g. the Dutch East India Company/United East Indies Company and Dutch West India Company, provided an infrastructure which was accessible to people with a scholarly interest in the exotic world.

European geographers celebrated the "discoveries" of Dutch travels. It was said that “mapmaking was one of the specialized intellectual weapons by which power could be gained, administered, given legitimacy, and codified.”

In the Golden Age of Dutch exploration and discovery (approximately 1590s–1720s), using their expertise in doing business, mapmaking, shipbuilding, seafaring and navigation, the Dutch traveled to the far corners of the world, leaving their language embedded in the names of many places. Dutch exploratory voyages resulted in the charting and revealing of largely unknown huge landmasses, vast waters, and far skies to the civilized world and undisputedly put their names on the published atlases.

The Dutch were celebrated for their map-making skills, and became renowned across Europe. As their cartography prospered in the early modern period, Dutch map makers such as Blaeu, Hondius, Janssonius and Montanus became references in cartographic circles across Europe, and their maps, atlases and globes were regarded as being of the highest quality.

Mapmakers in Amsterdam used designers, artists, and engravers to sell the most ornate and detailed maps on the market. Before the atlas was invented, wealthy intellectuals would purchase sheet maps one at a time, and hang them on their wall. Just like a work of art, people would pay exorbitant prices to display a famous “Blaeu” or “Ortelius” map. It made the buyers appear more cultured, intelligent, and classier than their peers.

With the introduction of the printing press, mapmakers might not have been able to buy new copperplates every time a geographic area would change. Instead, they would add new designs, re-used the old plates, or added new information somewhere on the map by hand-painting the information. Many mapmakers also dedicated their maps to wealthy or influential individuals in the hopes of selling the map at a higher price.

Please refer to the section on "Maps" on the "Aspects of Vermeer's Paintings" page.