How did mercator's map navigators?

The information used by the marine navigator, including latitude and longitude scales, topographical features

1) The Fall of the Roman and Han Empires were evidently the same, both ruleing in the first century of the Common Era. These empires showed great military power, striving for economical power, and their terroroties covered a vast majority of land. When the economy, trade began plummeting in Rome and China, Rome was devastated by this cause and was one of the reason's why it led to their collapes. China, also was affected, but, they were many self sufficient groups. This happened because Rome relied heavily on trade. As less trade began happening, the amount of taxes and good that were coming were insufficient. One major similarity was the Social unrest during their collapse. The Peasants became angered with the rise in taxes and started to revolt against China. On the other hand, the Romans did not struggle with revolts but instead religion. As the spead of Christianity happened, cruel punishments and consequence were given to those who believed in this religion.