French Photographer Discovers 120-Year-Old Time Capsule with Undeveloped Film, This is What He Found on Them – TechEBlog

French photographer Mathieu Stern discovered a 120-year-old time capsule in the basement of an old family home, and inside the antique box that dates back to the year 1900, were two glass plate negatives. After combing through the other items, which included coins, a paper doll, seashell, and even a letter, he decided to develop the glass plates using an classic photographic printing method called cyanotype. Read more for a video and additional information.

What did these two glass plate negatives reveal? Cats of course, which are assumed to be pets of the little girl who owned the antique box. On a related note, engineers still use the cyanotype process today as a simple and low-cost process to produce copies of drawings, better known as blueprints. The process makes use of two chemicals: ferric ammonium citrate and potassium ferricyanide.