Over the Edge of the World: Magellan's Terrifying Circumnavigation of the Globe

by Laurence Bergreen

Island tribes also studied birds for signs of land. By simply following a bird’s trail at the end of the day, when it flew to its nest after a day’s fishing on the open ocean, island navigators could reach land. They studied clouds. The higher islands in the Pacific interfere with the trade winds, causing mist and vapors to collect above the landmasses. Magellan’s lookout had seen this effect when he first spied land and was unable to distinguish the island of Guam from the surrounding clouds. Even the underside of clouds contained valuable information because they reflected the color of the ocean directly below. If the underside happened to be tinged with jade, it was likely reflecting the greenish shallow water covering an atoll or reef. They also sensed patterns in the placement of the islands, which tended to be scattered in long archipelagos; if they found one island, they would know approximately where to look for others. For celestial navigation, island tribes employed