Spain and Portugal were two nations that led the way in exploration and discovery, especially during the fourteenth and fifteenth centuries. Each country had its successes and its failures, and each country had its famous explorers. The focus of this paper is on one particular Portuguese explorer, Prince Henry the Navigator, and the tools and techniques he introduced to his sailors, which revolutionized sailing and furthered exploration more so than anyone else had done up to that point. Although Henry himself never actually set sail on these adventures, "under his direction many important expeditions were undertaken along the west coast of Africa (Encarta)." Henry was the son of Joao I, the king of Portugal at the time, and was driven to help his father find a faster way to the spice trade in the Far East. The Italians and the Arabs already had strong footholds there, and Henry wanted to ensure that Portugal gained one, too, in order that they might partake of the riches in slaves, spices, and gold to be had there.

The Portuguese are an adventurous people, and Henry knew that if he could just capitalize on this, he could drive his sailors to go farther and do more than anyone else had up to that point. From the Muslims, "[the Portuguese] had learned better ship design, cartography, sailing, and navigation and math skills (European Age of Exploration)." To that end, Henry established an observatory and the first school for navigators in Sagres, Portugal, where he lived. Before the sailors...

"Expeditions moved slowly due to the [sailors'] belief that waters at the equator were at the boiling point, that human skin turned black, and that sea monsters would engulf ships (Mariner's Museum)."
Henry could have reasoned that by knowing the seas better, the men would not be so afraid of the unseen dangers that lurked there. After all, it is human nature to fear what we don't know. Often, once the mystery surrounding something is revealed, the fear dissipates as well. Whatever his reasons were beyond sending the sailors to find a faster route to the Far East, Henry did give these men some astounding tools and technology for the time.

One new navigation tool was dead reckoning, in which a sailor essentially deduces his way across the ocean. One source (Pickering) explains dead reckoning as follows:

In [dead reckoning], the navigator finds his position by measuring the course and distance he has sailed from some known point. Starting from a known point, such as a port, the navigator measures out his course and distance from that point on a chart, pricking the chart with a pin to mark the new position. Each day's ending position would be the starting point for the next day's course-and-distance measurement.

This method does not always work, however, especially when there is no known point from which to begin the figuring, for example,…