While attempting to use celestial navigation, one of the most important tools used by Columbus was a quadrant. A quadrant is a tool used for taking measurements of altitude. Unfortunately, celestial navigation proved to be difficult for Columbus and he often ended up with false readings.
Columbus used a variety of other tools on his journeys. He used a sandglass to measure time and a nocturnal, which was a tool used to tell the time of night by the rotation of the stars.Learn more about Exploration & Imperialism