These ancient stereo drawings were found in 1859 by the brothers Brown in the Wicar Museum at Lille, in France:
they are a pair of drawings supposed to be made by the Florentine painter Jacopo Chimenti di Empoli (1554-1640),
with reference numbers 215 and 216.
These drawings were published separately, but when you look at them with a stereo viewer, you obviously
see a stereoscopic image. This has been vigorously disputed, but you can judge for yourself.
It is difficult to argue about the intentions of the artist who is long dead.
If you try to create a stereo image this way, by hand, you will likely get a similarly disappointing result.
Perhaps this is why stereo drawings never caught on. While many consider this a big hoax,
it may also represent a single artist's quick attempt at a stereo drawing.
Or it could be a coincidence.
The 13th Century image below is from "Illuminated Manuscripts"
in the Bodlein Library Oxford, in the third volume of Otto Pacht and J.J.G. Alexander,
Oxford at the Clarendon Press, 1973, page 39, plate XXXV Nr. 415.
The stereo is obvious in this pair, but perhaps, in context, these may be coincidental.
These images were published in the monthly bulletin of the French Stereo-Club, Nr. 673, October 1983.
They were provided to me by Olivier Cahen. Many thanks.