There are three ... and maybe a fourth (we're looking).
If you don't know that the "Magic Lantern" viewers were, then these are probably not of interest. They were early - late 1800's - early 1900's - "slide projectors". The link is to one I found on ETSY ... just for reference. The images were saved on glass "slides" and then could be projected on screen or wall.
All three of these Magic Lantern Slides; all with bison in them, for one money. They were $35, $45 and $55 - $135 and they were bargains at those prices ... now all three for $35!
If the fourth one shows up I will include it, too. Heck of a heck of a deal! Just more of the historic fascination with bison.