Today's lesson continued the focus on the age of exploration. Mercer read about Two of Christopher Columbus' ships, the Pinta and Nina, which were caravels. He learned about explorers such as Bartolomeu Diaz and Vasco da Gama, who also chose to sail caravels, and why the ships were so popular because they had two to three square or triangular masts that could sail into, or against, the wind. This made it a mighty, fast-moving ship, about twice the speed of the oar-driven galley ships. It also required fewer men to operate, and with less crew, labor was cheaper, and there was more space left for cargo. Mercer was on task.