Some of the modern geophysicists probably know Carl Stormer (1874-1957), he was a Norwegian geophysicist, mathematician, aurora researcher, foreign member of the Royal Society and a corresponding member of the French Academy of Sciences. He was also known as an amateur street photographer. He used a C.P. Stirn Concealed Vest spy camera to make photos of random people on the street.
He got this camera in 1893, and now there are more than a hundred glass plates known with photos made by this camera. A couple of examples:
Henrik Ibsen, major 19th-century Norwegian playwright of realistic drama and poet.
Kristian Birkeland, future teacher and coworker of Carl. You can find this face on the Norwegian 200 krones note.
Just some random girls walking around the Oslo streets.
Here is the YouTube video with some other shots by Carl.
This is a translation of a Russian language entry in the LiveJournal.