Welcome to Textbook Sleep, the Maximum-Strength Sleep Aid, where I read extremely boring public-domain textbooks to help people fall asleep. We continue with General Science by Bertha M. Clark, Ph.D. Specifically, we’ll hear what Dr. Clark has to say about photography, or I will anyway—you’ll be lulled to sleep, hearing me speak of movable convex lenses, sodium thiosulphite, and sensitive plates left to dry in dark rooms.
Today we all carry a camera in our pockets, but in 1912, when this textbook was written, a photograph was far more complicated to take. Which was great in that no one could take a selfie, let alone post it on so-called social media. Still, it’s all terribly tedious, which is just perfect for our purposes.
Smile. And sleep.
This recording will end quietly.
