The narrow streight into the Euxine sea was a passage of difficult navigation. This was the reason, that upon each side there were temples and sacred columns erected to the Deity of the country, in order to obtain his assistance. And there is room to think, that the pillars and obelisks were made use of for beacons, and that every temple was a Pharos. They seem to have been erected at the entrance of harbours; and upon eminences along the coasts in most countries. The pillars of Hercules were of this sort, and undoubtedly for the same purpose. They were not built by him; but erected to his honour by people who worshipped him, and who were called Herculeans. [794]Εθος γαρ παλαιον ὑπηρξε το τιθεσθαι τοιουτους ορους, καθαπερ ὁι Ρηγινοι την στηλιδα εθεσαν, την επι τῳ πορθμῳ κειμενην, πυργον τι. Και ο Πελωρος λεγομενος πυργος αντικειται τῃ ταυτῃ στηλιδι. _For it was a custom_, says Strabo, _among the antients, to erect this kind of land-marks, such as the pillar at Rhegium, near the foot of Italy: which is a kind of tower, and was raised by the people of Rhegium at the streight where the passage was to Sicily. Directly opposite stood another building of the same sort, called the tower of Pelorus._ Such Pillars were by the Iberians styled Herculean, because they were sacred to Hercules; under which title they worshipped the chief Deity. Some of these were near Gades, and Onoba[795], Κατ' Ονοβαν της Ιβηριας: others were erected still higher, on the coast of Lusitania. This caused an idle dispute between Eratosthenes, Dicæarchus, and [796]others, in order to determine which were the genuine pillars of Hercules: as if they were not all equally genuine; all denominated from the Deity of the country. Two of the most celebrated stood upon each side of the Mediterranean at the noted passage called fretum Gaditanum--κατα τα ακρα του πορθμου. That on the Mauritanian side was called Abyla, from Ab-El, parens Sol: the other in Iberia had the name of[797] Calpe. This was an obelisk or tower, and a compound of Ca-Alpe, and signifies the house, or cavern of the same oracular God: for it was built near a cave; and all such recesses were esteemed to be oracular. At places of this sort mariners used to come on shore to make their offerings; and to inquire about the success of their voyage. They more especially resorted to those towers, and pillars, which stood at the entrance of their own havens. Nobody, says [798]Arrian, will venture to quit his harbour without paying due offerings to the Gods, and invoking their favour. Helenus in Virgil charges Æneas, whatever may be the consequence, not to neglect consulting the oracle at Cuma. [799]Hic tibi ne qua moræ fuerint dispendia tanti, Quamvis increpitent socij, et vi cursus in altum Vela vocet, possisque sinus implere secundos, Quin adeas vatem, precibusque oracula poscas.