On the cover of the 18th century book, a UFO

In the palette of the book, which was created back in the eighteenth century, a painted UFO was found. 

According to ufologists, this is another proof that even three hundred years ago our planet was still visited by aliens.

The book on which they found the "flying saucer", surrounded by sparkling lightning, was published in 1716. It is a treatise on mathematics by Johann Funk.

On the cover of the book you can find a UFO in the "classic" 

already for modern man style, that's how we imagine an alien alien ship.

Not everyone agrees with the fact that aliens visited our planet Earth in the 1700s, but, as we see, there were people who believed in this in the eighteenth century. Already then, as now. The world is divided into two halves, those who believe, 
and those who do not believe in UFOs.
In addition, ufologists are asked questions about the fact that already in the 18th century the aliens had such advanced technologies? Have they remained the same after three hundred years? Have they stopped in their own development? These issues are now open.