Gerard Mercator

Greenland from J. G. Bartholomew's 1917 atlas

The map above shows the Mercator projection used in a 1917 atlas. Find Greenland (Groenland) on the map from de Isle's atlas of c.1740 (below). How do the two maps compare? Bear in mind that some of the differences will be because people had mapped the world more accurately by 1917 than they had by 1740. Click on the pictures to see the full world maps.

Greenland from de L'Isle's atlas c.1740

Gerard Mercator and Jodocus Hondius

Gerard Mercator is one of the most famous map-makers in history. In the picture above he is the man on the left with the long beard. This picture comes from the 1613 edition of Mercator’s atlas. Click on the image to see more.

Mercator’s projection

In 1569 Mercator issued a new world map. This was important because he used a new projection to draw it. Projection refers to the method by which a 3D object, the world, is turned into a 2D map.

The two maps on the left show the difference between the Mercator projection (top) and another projection (below). Mercator’s projection:

  • is rectangular rather than circular
  • has straight lines of latitude and longitude rather than curved ones

The drawback of Mercator's projection is that it makes land masses further away from the equator look bigger. So countries nearer the poles, such as Greenland, appear far larger than they really are.

Mercator designed this projection for sailors. The straight lines of latitude and longtitude meant that they could plot a straight line course across a long distance (such as across the Atlantic) without having to change direction. They could use one compass direction for the whole journey. Using a curved map they had to keep taking new compass bearings and changing direction. By the 1600s many sailors were using maps drawn with the Mercator projection. Later it became popular for making school atlases.

Mercator’s atlas

Mercator’s other important achievement was his atlas of 1585-1595. It was the first collection of maps to be called an atlas.

When Mercator died in 1587 his family continued the business. In 1606 they sold it to the Hondius family. The man opposite Mercator in the picture at the top of the page is Jodocus Hondius. The Hondius family used the engraved copper plates from Mercator’s atlas to publish a new version of it. The copy in St John’s College Library is the fourth edition of this version published in 1613.

Hondius' printer's device

The picture of the dog with a globe is from the title page of the Hondius’ 1613 edition of Mercator’s atlas. The Latin under the dog translates as "Printed at the sign of the watchful dog". This is Hondius’ printer’s mark. It puns on his surname (think of the word ‘hound’).

The Latin around the globe means “I use, I describe, I adorn, I censure and I choose faithfully”. This probably refers to Mercator and Hondius’ scholarly approach to the sources they used to make their maps. Click on the picture to see the whole titlepage.