Marine treasures and scientific instruments

Magellano made Pigafetta a special agent, tasked with keeping a diary of everything that happened on the voyage.

The manuscript is essentially the ship’s log compiled by Magellan's Vicentino navigator.

The precious portolans or, more accurately, portolan charts, occupy a special place in the collection.

It is worth pointing out that the term "portolan" usually used to describe these charts is inaccurate, not to say incorrect.

In fact, the portolan should be understood as a book, or rather codex, which – in the absence of any nautical charts in medieval times – literally describes the coastline, its features, reference points, ports and landing places.

In short, we would consider them to be a guide for navigators.

These usually started out as travel reports, and can be considered to be the descendants of the ancient peripli.

The oldest charts can be found in a 1373 atlas, which includes a map of the world dated 1367, made by the Venetian Francesco Pizzigano who was, together with his brother (or brothers), already a noted cartographer.

Vincenzo Pizzigano, who had a workshop in Venice, was probably just a "copier" rather than a genuine cartographer. The Ambrosiana atlas contains five small colour portolan charts (12.5 x 15.1 cm) and four charts by an anonymous author.

The small dimensions of atlases like this suggest that they were educational volumes, aimed at the more cultivated people of the time, rather than navigators.

On the other hand, it has also been conjectured that their size made them more practical. In fact, since larger charts required a considerable amount of space to spread them out and were more subject to tearing or becoming crumpled, the pages of the atlas, which were generally glued onto cardboard or wooden boards, lay flatter and were less prone to deterioration after use, once they had been closed.

he Great Portolan Chart of Jacopo Vesconte Maggiolo from Genoa is absolutely spectacular due to its size and the artistic beauty of the drawings.

The chart, on a parchment measuring 124.5 x 86.7 cm, depicts the Mediterranean area and the eastern coasts of the North Atlantic in colour.

Eight ships with sails unfurled have been drawn in the Atlantic.

Asia and Africa feature ten richly damasked royal pavilions.

Eight of them are in Africa, and the legendary "Prester John" is depicted beneath the sixth, next to the inscription "Ethiopia".

The ninth is in Asia and represents "The Great Turk"

The last, straddling Asia and Europe, represents the "King of Tartary".

The cities are represented by walls with towers and flags.

The two large decorative frames enclosing the chart are a further impressive aesthetic detail that demonstrates the refinement of this work.

A Madonna seated on a throne cradling her Child is depicted in the left-hand border of the parchment.

In addition to the atlases and portolan charts, the Ambrosiana also holds relics, astrolabes, and armillary spheres from the collection of the famous seventeenth-century naturalist Manfredo Settala. These instruments, especially the astrolabes, were formerly used in navigation to determine the position of the stars.

This astrolabe allows the user to determine the position of thirty-eight stars.

A curious detail: a dragon's head can be seen in the sign of Capricorn. Its body is in the form of a circle, and ends in the Scorpio constellation.

This could be an uroboros, a very ancient, complex symbol that represents a snake or dragon biting its tail, continually recreating itself and forming a circle of eternal return.

An armillary sphere is a model of the firmament according to the Ptolemaic system, consisting of metallic circles (armilla in Latin) with a small globe in the centre representing the Earth.

These instruments were used to study and illustrate the movement of celestial bodies around the Earth. This armilla bears the signature of Manfredo Settala and the date 1644.

This armillary sphere was probably made of silver-plated brass and illustrates the Copernican theory of lunar motion. In fact, Copernicus tried to illustrate the irregularity of this motion with a system of epicycles.

It is a very unusual and extremely rare type of armillary sphere, dating back to the first half of the seventeenth century.