Compared to Ted Chiang's "Tower of Babylon," how can you prove that The Travels of Sir John Mandeville is or is not science fiction based on examples from each piece?

Ted Chiang's "Tower of Babylon" is clearly science fiction. The story, based on Babylonian cosmology, tells the story of Hillalum and Nanni, two men who ascend the Tower of Babylon and enter what is clearly a world created by science fiction. For example, they eventually ascend to the height of the moon: 


"Before long, they were at precisely the same level as the moon when it passed; they had reached the height of the first of the celestial bodies. They squinted at the moon's pitted face, marveled at its stately motion that scorned any support."

The climbers keep ascending until they reach the vault of heaven, which is described in the following way:


"The vault itself remained just above a man's outstretched fingertips; it felt smooth and cool when one leapt up to touch it. It seemed to be made of fine-grained white granite, unmarred and utterly featureless."

These elements of the story, including the vault of heaven, come from Babylonian cosmology and are in the realm of science fiction.
The Travels of Sir John Mandeville is widely considered to be a fake, and experts still disagree about its author. The book, which was published around 1350 or 1360, chronicles the journey of an English knight to Persia, Turkey, India, Egypt, and Ethiopia. While the book was very popular in its time, it is also clearly a work of science fiction (though that was not apparent to readers at the time). The text details fantastical people such as men with horns, people who have the heads of dogs, and people with eyes in their shoulders, among other oddities. The geography described in the book is, however, rather accurate, and these fantastical details are accompanied by drawings that might have seemed real to the original readership.
The details in the travelogue are clearly fictional. Here is a description of the woman that the author encountered in Chapter 4 on his way from Constantinople to Jerusalem:

"And some men say, that in the isle of Lango is yet the daughter of Ypocras, in form and likeness of a great dragon, that is a hundred fathom of length, as men say, for I have not seen her. And they of the isles call her Lady of the Land. And she lieth in an old castle, in a cave, and sheweth twice or thrice in the year, and she doth no harm to no man, but if men do her harm. And she was thus changed and transformed, from a fair damosel, into likeness of a dragon, by a goddess that was clept Diana."

The woman who was changed into a dragon is clearly a creation that belongs in the realm of science fiction. In Chapter VI, the author describes the Tower of Babylon in the following way: "But it is full long since that any man durst nigh to the tower; for it is all desert and full of dragons and great serpents, and full of diverse venomous beasts all about." This is a fantastical detail, as the author says that the land around the tower is full of dragons and serpents. While readers of the day might have believed these tales, they are obviously fantasy.  
Sources:
Milton, Giles. (1996). The Riddle and the Knight: In Search of Sir John Mandeville, the World's Greatest Traveller. Picador USA.