Sunday, September 5, 2010

The Compass Rose

Mediterranean Sea---I have always loved maps and the compass. So much so, that when I had my pool refinished, I insisted on putting in a mosaic compass rose on the bottom with true directions. I designed it and laid many of the tile pieces myself. Unfortunately the timing of having my pool drained and the bottom fiberglass hammered off could not have come at a worse time: between Hurricane Charlie and Francis in 2004. So the pool company was less than eager to stop so I could lay a tile design, nevertheless, they did, and it is there today.


So when I found a necklace in Sardinia of not only a tiny compass but also the Rose of the Winds I knew it was a perfect keepsake. I also decided to learn more about the Compass Rose, Rose of the Winds and Compass.

According to what I found:

The Compass Rose is a figure on a map, a nautical chart or a paving used to display the orientation of the cardinal directions, — north, south, east, and west. It is also the term for the graduated markings found on the traditional magnetic compass. Today, the idea of a compass rose is found on, or featured in, almost all navigation systems.

A Rose of the Winds is an ancient version of a compass rose which personified compass directions as winds with individual names a fountain in Taranto, Italy was inspired by and named after the Rose of the Winds. The boat wintered in the Bay of Taranto and this is where I met them. I wish I had known this then, I would have made a trip to see this fountain!
Ancient Compasses used the lodestone, long known to attract metal. The first magnetic compass was a piece of lodestone or a sliver of iron that had been rubbed on it and was placed on one end of a stick of wood rotating until the end supporting the rock or iron pointed approximately to the North Star. It is not known exactly where or when the formal magnetic compass originated. However, what little unclear evidence has been found indicates the compass was refined in Italy circa 1200AD. It was probably developed by combining the wind rose and the lodestone. From this device it is supposed the compass rose evolved. In time, a wind rose was glued to the top of a lodestone and placed in a covered container of water. Later, oils were used instead of water to stabilize the compass disk from erratic movement. Then it was found you could magnetize needles and glue them to the bottom of the disk. These needles had to be re-magnetized periodically to maintain a sufficient level of magnetism.

Like the wind rose, the compass rose was coincidentally designed in a fashion that resembled the rose flower. It helped to orient a map in the proper reading direction and gave the relative directions for certain points on the chart.

Before compass roses were used on maps, lines were drawn from central points. These lines were hard to follow since there were usually many of these lines intersecting each other on one map. The rose design was typically drawn in a way that made it easier to follow the directional lines.

Having good maps that were easier to read and which were developed using the magnetic compass made it much more efficient to trade for goods in faraway lands and over the open seas. Direct routes could be established, and navigation in bad weather enabled transportation to take place year round instead of only on fair weather days during the warmer seasons.

In the Middle Ages, the names of the winds were commonly known throughout the Mediterranean countries as tramontana (N), greco (NE), levante (E), siroco (SE), ostro (S), libeccio (SW), ponente (W) and maestro (NW)


Written in the sand at Edwards Air Force Base
 The wind names of the directions NE, SE, SO (southwest) and NO (northwest) derived from the fact that in the first mappings of the Mediterranean area, the compass rose was depicted at the center of the Ionian Sea near the island of Malta, thus becoming the reference point to indicate the direction of winds.

Vessels were originally driven from downwind, In that position, the ships arriving from NE, came about from Greece, which included the southern coast of the Balkan and eastern Turkey, hence the name "Gregale".

For NE-SW wind. SE ships arrived from Syria, hence the name for the "Sirocco" wind.

To SW there is Libya, a name formerly used also for Tunisia and Algeria, hence the name "Libeccio" for winds from SW to NE.

Finally the ships sailing from Rome came from NW (often circumnavigating Sicily rather than facing the Strait of Messina and our experience in this area explains why!) i.e. from "Mistral" or “Maestro” (Magistra in Latin),

Early roses were depicted with 12 points at 30° each, as was favored by the Romans. The Chinese divided the compass into 12 major directions based on the signs of the Zodiac

In the Middle Ages map makers moved to the 16-point rose complaining that sailors did not have the education to understand the previous design.

The Arab sailors navigated by a 32-point compass rose during the Middle Ages

Originally, this device was used to indicate the directions of the winds but the 32 points of the compass rose came from the directions of the eight major winds, the eight half-winds and the sixteen quarter winds.

Some believed the numbers of the points started at North; however, it actually started at East. This was because in relation to Western Europe, Jerusalem was in the east and therefore East was considered the primary direction. Similarly, on old maps the east was marked with an L for Levante, or with a Christian cross indicating the direction of Jerusalem from the point of view of circa Mediterranean countries.

The compass rose has appeared on charts and maps since the 1300’s when the portolan charts first made their appearance.

Replica of a 32-point compass rose from a chart by Jorge de Aguiar (1492), the oldest personally signed and dated Portuguese nautical chart. The first letters of the main winds are composed to form T(E)MPLOS, an acronym of the Knights Templar Navy.

The contemporary compass rose appears as two rings, one smaller and set inside the other. The outside ring denotes True North, the geographical location of the North Pole, while the smaller inside ring denotes Magnetic North, which refers to the direction that the North Pole of a magnetic object (as found in a compass) will point. The angular difference between true and magnetic north is called variation, which varies depending on location. The angular difference between magnetic heading and compass heading is called deviation which varies by vessel and its heading.

Red, blue, black, and green were the most common colors used in the compass rose. On a rolling ship at night by the light of a flickering lamp, these figures had to be clearly visible. Therefore the eight principle points of the compass are usually shown on the compass rose in black which stands out easily. Against this background, the points representing the half-winds are typically colored in blue or green and since the quarter wind points are the smallest, they are usually colored red.



References: The Annapolis Book of Seamanship by John Rousmaniere, Wikipedia, Origins of the Compass Rose by Bill Thoen as found on gisnet.com, compassrosegeocoin.com

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