Yesterday I was visiting the museum of cinema in #Torino. I was amazed to discover that Camille Flammarion was using the magic lantern during his scientific conferences:
"In 1866 I started using limelight projection devices in my astronomy lectures: their bright images were an effective complement every to illustrate astronomic principles... We started by projecting the 30 images from my publication The Wonders of the Heavens which were the entire content of my illustrated conferences."
... the first PowerPoint presentation in human history!