Roman Navigation

[M. Porcius Cato]

Dava Sobel wrote a fabulous little gem of a book called "Longitude", which records some of the naval disasters that occurred as a result of navigators not being able to determine their longitude. Does anyone know how the Romans managed to sail along longitude lines without running into trouble? They couldn't exactly hug the coast from Ostia to Alexandria. Or did they?

[Jimbow]

They couldn't exactly hug the coast from Ostia to Alexandria. Or did they?

Pretty much, I believe?

Edited December 30, 2005 by Jimbow

[FLavius Valerius Constantinus]

Dava Sobel wrote a fabulous little gem of a book called "Longitude", which records some of the naval disasters that occurred as a result of navigators not being able to determine their longitude. Does anyone know how the Romans managed to sail along longitude lines without running into trouble? They couldn't exactly hug the coast from Ostia to Alexandria. Or did they?

 

Here's the most probably answer(Taken from Microsoft Encarta Online):

 

VI History of Navigation

 

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The early seafarers who first started plying the water about 3500 bc rarely left sight of land. At night they pulled their reed boats up on beaches or anchored in safe harbors identified by landmarks, such as hills, tall trees, or partially submerged rocks. They gave these landmarks colorful names, many of which persist to this day. For example, a sailor may come across rocks or islands named Lone Rock or Sow and Pigs (a big rock surrounded by many little ones).

 

From the time they took to the sea, mariners developed devices to help them navigate safely at increasingly long distances from land. One of the first was the sounding pole, carried on board to gauge water depth. They also made the first aids to navigation, which consisted of piles of rocks on shore or stakes driven into the sea bottom. Because few maps were available at the time, early navigators relied heavily on memory and on written guides called pilot books. Pilot books provided information about coastal piloting in ancient Greece, Rome, and Egypt

Edited December 31, 2005 by FLavius Valerius Constantinus

[Tobias]

I can't add much to FVC's very comprehensive account. Although slightly unrelated to the Romans, i recall a chap named Pytheas; a Greek explorer and geographer who made a voyage to northwestern Europe. He circumnavigated Great Britain between 330 and 320 BC, and was supposed to have reached a place called "Ultima Thule" (possibly Iceland, or parts of the Norwegian coast.) Pytheas was the first to document such phenomena as auroras, polar ice and the Midnight Sun. According to Wikipedia; "Pytheas estimated the circumference of Great Britain within 2.5% of modern estimates. There is some evidence he used the Pole Star to fix latitude and understood the relationships between tides and phases of the Moon. In northern Spain, he studied the tides, and may have discovered that they are caused by the Moon. This discovery was known to Posidonius."

I daresay such methods were used by the Romans quite a bit and instinct, estimation and luck would also have been relied upon.

Edited December 31, 2005 by Tobias

[M. Porcius Cato]

I'm a bit skeptical of the MSN Encarta account. What it says about Polynesian navigation, for example, doesn't jibe very well with the anthropological studies of Hutchins ("Cognition in the Wild"). I also wonder whether the temperature of the winds can be gauged by the human senses enough to determine how far north or south one is. I'll keep looking.