Letters, Paolo Toscanelli maps and Columbus calculations

This XXI part of the series "Popular Science Essays": The correspondence with Toscanelli and the sending of maps to Portugal by historians is called into question. They claim that Toscanelli was not at all a supporter of the Atlantic Ocean expedition. There is only a copy (rewritten by Columbus) of his letter, which says that from Lisbon "to the great and magnificent city of Kinshasa" (Chinese Hangzhou) - 26 times 250 miles, ie 6.5 thousand miles. Let's take the old Roman mile at 1481 meters and get the specified distance in kilometers - 9.6 thousand. In reality, from Lisbon to Hangzhou, west in a straight line, not 9.6, but more than 20 thousand miles, ie more than two times more.In letters of 1498 and 1503, sent to the King and Queen of Spain, the Admiral described in detail their geographical representations, formed 15-20 years before. Referring to Ptolemy, as well as the medieval theologian and geographer P. d'Ailla, he wrote that the land as a whole is spherical. The second letter (no date), addressed to Columbus, absolutely no specific information contained. Toscanelli graciously endorsed "a bold and grandiose plan to sail to the eastern countries on the western route". He considered the plan to be correct and reliable.