This is the last post illustrating the 19th Century Magic Lantern Slides recently found in Scovel Hall of Wooster’s Geology Department. Please see the December 2 post and the week before for details. To review, these slides are 4×8 inches with the image fixed on glass bolted into a thin slab of wood with metal rings. They are chromolithograph slides, each stamped “T.H. McAllister, Optician, N.Y.”. McAllister was the most prominent of many American producers of lantern slides in the late 19th century.
This last set of slides in our collection was apparently used in our old “Historical Geology” courses to evoke the geological time periods. The top image is simply labeled “Devonian“. The trees on the right appear to be towering lycopods, a kind of seedless vascular plant. They were common in the Devonian and are still around today. I can’t tell what the other plants are in the image. The rapid rise of large plants in the Middle Devonian has been called the “Devonian Explosion”. These early forests had significant effects on atmospheric composition, soil formation, erosion, and sediment transport.
[UPDATE: Please see the excellent comments by Ben Creisler. He has given us much new information and numerous links explaining the history of these images. I’ve left my amateur text in place only to record the original post! MW]
“Carboniferous” is the title of this slide. It is dramatic, seemingly showing a Carboniferous forest dominated by ferns being torn apart by a swelling tide. Could this be a comment on the interbedding of marine and terrestrial rock units so common in the Upper Carboniferous of North America?
Ferns are again in the foreground of this Permian scene. I have no explanation for the mountainous seashore landscape, except that the red color of the rocks may represent the New Red Sandstone of Great Britain.
This slide is enigmatically labeled “Transition Period”. I suspect it represents the Triassic, a period just after the Permian and thus part of the transition into the Mesozoic. The shrubby plants in the foreground appear to be cycads with massive yellow cones emerging from their tops.
This image of the “Eocene” is the first of these period slides to depict animals (the herd of ungulates across the river and the bird in the foreground). This may mean these slides were meant to show the progression of plant life over geological time. The forests here look dominated by conifers and angiosperms.
This is a “Miocene” image. I don’t know how I’d distinguish it from the Eocene view above.
Our final slide shows what the “Drift Period”, which is clearly the Pleistocene. Not only do we have cave bears in the foreground and a herd of bison in the river, there seems to be a massive pile of ice in the left rear!
I have not discovered the artist responsible for these illustrations. If you know, please tell me in the comments!
[UPDATE: Please see excellent information and links by Ben Creisler in the comments below. Thanks, Ben!]