Isaac Newton thought of the Earth as not a perfect sphere but as a “geoid” - an ellipsoid that is flat at the poles and slightly convex toward the equator. The “geoid” concept reappears in the history of the French geodetic measuring missions which we'll look at in a moment.

Moving to the right, you can see the construction of the first Equatorial Museum monument. The first monument was 10 meters high and was later moved to a town called Calacalí. The current monument is 30 meters high and was built by Luis Tufiño, an Ecuadorian engineer and geographer.

Next, let's take a look at the French geodetic missions. Their first mission was to measure the meridian from 0 degrees latitude to the North Pole so as to confirm that the Earth is a “geoid” and to identify the locations of the equatorial belt and the equatorial line.

The second mission of the French was to extend their measurements from a region called Tulcán in Ecuador to a region called Paita in Peru, using the technology of the 19th century. This mission allowed them to confirm the results of the first mission.

Now let's go downstairs.