What is in this image? Describe it as if you were explaining it to someone from the 15th century.

This depiction shows a fantastical carriage, unlike any horse-drawn vehicle or ship that you might know. Imagine a large, metal bird, crafted by skilled artisans, with wings that spread wide and a body that houses an ingenious mechanism allowing it to soar high above the clouds, much higher than any bird. This metallic bird is not powered by beasts of burden or the wind, but by its own internal mechanisms, mysterious and powerful, that enable it to traverse great distances in the sky at speeds unimaginable. It rests upon small wheels, suggesting it can move on land, but its true domain is the vast expanse above.