Analysis of information sources in references of the Wikipedia article "Piri Reis map" in English language version.
In arguing that there was no known way of establishing longitude in Columbus's day and until the mid-eighteenth century (p. 41-2) he overlooks the sailor's skill in estimating longitude by dead-reckoning.
In arguing that there was no known way of establishing longitude in Columbus's day and until the mid-eighteenth century (p. 41-2) he overlooks the sailor's skill in estimating longitude by dead-reckoning.