Visual aids a century before PowerPoint

Teaching Sheets 076

This delicate sheet measuring approximately 4 x 6 metric feet, depicts various Devonian flora, including including Hymenophyllites, Cyclopteris, and Neuropteris. Dawson described this ancient landscape in: On the flora of the Devonian Period in Northeastern North America (1862); Further observations on the Devonian plants of Maine, Gaspé, and New York (1863); and Acadian Geology (1878).

Long, long before PowerPoint was even dreamed of, back when the “magic lantern” presentation (the great granddaddy of the slide show) was “wow” technology, Sir John William Dawson concocted a novel way of enlivening lectures with attention-catching visual aids. Dawson, McGill Principal, distinguished scientist and founder of the Redpath Museum, illustrated his lectures with “teaching sheets,” linen sheets measuring approximately four feet by six showing beautifully painted images of long vanished plants, animals and fossils. This illustration, entitled Vegetation of the Devonian Period, is one of 34 teaching sheets now in the McGill University Archives.

Teaching sheets probably tacked or pinned up when in use
The images were probably painted by Dawson’s daughter, Anna Lois Dawson, a noted contemporary artist, using black India ink. Most of the sheets have small puncture holes around the edges, suggesting that they were pinned or tacked up for viewing. They were probably produced between 1875 and 1885, at the height of Dawson’s scientific career.

Teaching sheets in the McGill collection fall into five general categories: the Joggins Coal Formation (where many fossils were discovered); Devonian and Carboniferous Flora (depicting vegetation from these periods); Trackways and Burrowers (showing footprints of early reptiles and trace fossils of invertebrates); Geological Images (depicting cross sections of Canadian geological formations) and Aboriginal Tools.

Once the last word in visual aids for the lecture hall, these detailed teaching sheets are now historical artifacts in their own right, and reminders of McGill’s long tradition of science education.


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