During a Sunday walk on Monte Santa Croce between the Ligurian villages of Pieve Ligure and San Bernardo, we came across a “MIRA”… well, as science divulgers we are, we took the opportunity to tell you about the unique history of the compass! A fundamental and indispensable tool for sailors and anyone who wants to travel.
The Rose of the Winds on Monte Croce
Under the pergola of the Monte Santa Croce shelter (518 m.), there is a “MIRA”…a metal wind rose on which are engraved the names of the places (joined by concentric circles)that can be admired from that point.
On this summit of Monte Santa Croce is the small church dedicated to the “Nostra Signora della Guardia,” built in the early nineteenth century. In the medieval period (the first documents date back to 1200), a hospice (the Latin word “hospitium” means place of hospitality) was built here for pilgrims traveling along the Italian pilgrimage routes.
A brief History of the Compass
Looking at the metal wind rose, another object that arrived in Europe in the Middle Ages (more precisely in the 12th century) came to our mind. Aka, the compass 🧭. Its history is truly fascinating! Used by navigators (at the time, navigation by sea was the fastest means of transport), illustrious figures such as Giordano da Pisa1, Giovanni da Buti, Flavio Biondo, Giambattista Pio, and also …. Dante speak of this instrument.
In Canto XII of Paradiso, the great Italian poet wrote:
“from the core of one of these new lights,
as the north star makes a compass needle veer,
rose a voice that made me turn to where it came from.”
The compass, whose name derives from “buxula” (box) and “buxus” (boxwood), was, in fact, a magnetic needle (or magnetic material ) contained in a boxwood box and placed in a sheltered position of the ship. It was a fundamental and indispensable aid for sailors and was used to identify the cardinal points.
Traditionally, the invention of the compass comes attributed to the Amalfi navigator Flavio Gioia2, but its historical origins would instead be traced back to the 4th century AD in China, from which it reached Europe only in the 12th century through the Arabs and, subsequently, the Amalfitans themselves.
Why was boxwood initially used?
The box that contained the compass was made with boxwood as this evergreen shrub (Boxus sempervirens) present in the Mediterranean flora was used for the compactness and hardness of its wood. Boxwood was used to make small and precious boxes for storing measuring instruments or small wooden parts of scientific instruments, but not big things because boxwood didn’t grow taller than 4-5 meters.
Reading the compass takes work.
Reading the compass was challenging: its needle pointed to magnetic north, which often didn’t coincide with geographic north; furthermore, it could be disturbed by large ferrous masses – such as, for example, those that made up the hull of the ship. An instrument called a dromoscope was then invented. It was a calculating tool consisting of two rotating and superimposed “wind roses,” which realigned and corrected the values detected by the compass.
The compass must be horizontal.
Furthermore, a compass on a ship is subject to fluctuations due to navigation. However, we know that we must keep it horizontal to read it. Well, to solve this problem, the gimbal was used. This was a mount formed by two hinged mobile rings. With this mounting system, compasses and nautical clocks remained constantly oriented in the horizontal plane, despite the ship’s movements.
Finally, we enjoyed a splendid panorama of the Ligurian Riviera under the pergola of the Monte Santa Croce shelter, resting from the rather tiring climb 😅. Then we took some focaccia and a few squares of chocolate out of the backpack… but we promise we won’t tell you their history.
At least for this time!
