Skip to content
All chapters

Chapter 01

Projection – Image – Information: The Lost Power of Slides and Their Employment in Scientific Presentations in the First Half of the 20th Century

Authors: Michal V. Šimůnek — Miloš Hořejš

When an image became part of a scientific argument.

Chapter 01
A 19th-century glass magic lantern slide with a hand-coloured geological illustration, set in a wooden frame.
Magic Lantern Slide Geological — photograph of a 19th-century geological slide. Wilson44691, via Wikimedia Commons. CC0 1.0. Illustrative reference image; not reproduced from the publication.

Look beyond the image

In scientific lectures, images could make complex subjects visible to an entire audience. A slide was more than an illustration: projected at scale and accompanied by a speaker's words, it became part of how evidence was presented and ideas were explained.

Looking at historical slides invites us to ask not only what they depict, but also how they were selected, arranged and interpreted. The technology may have changed, but the relationship between images, information and trust remains relevant.

One idea to uncover

Questions to explore

  1. What changes when a small photograph becomes a room-sized image?
  2. How does a lecturer guide what the audience notices?
  3. Can the same image support different interpretations?

This is a digital companion, not a reproduction of the published chapter.