This map is part of the atlas published by John George Bartholomew in 1911 under the title A literary and historical atlas of America. This representation combines the map of the Atlantic Ocean described by Paolo dal Pozzo Toscanelli in 1474, in orange, with a representation of America in its correct position in relation to Toscanelli's map.
The original map by Paolo dal Pozzo Toscanelli has been lost, but descriptions of it have been preserved. It is known that this map was first sent by Toscanelli to Fernão Martins in 1474 and later to Christopher Columbus. This was a key event in the planning of the voyage that led to the arrival of Europeans in America in 1492.
Toscanelli overestimated the actual size of Asia on his map. Similarly, Christopher Columbus miscalculated the actual size of the Earth, which together led Columbus to embark on a voyage and arrive by chance in America, even though he planned and thought he had reached East Asia.
In this article There is more information about the history of this map linked to Christopher Columbus.
Sources
Español 
English (UK)