GUMSHOE: Stanhopes
In 1857, a French photographer named René Dagron combined the hot new fad of microphotography and a 50 year old magnifying device called a Stanhope lens to come up with a simple inexpensive way of embedding tiny photographs into a wide range of gewgaws. Stanhope lenses are small enough to embed within rings, watch keys, pocket knives, charms, and so on. Dagron was also an entrepreneur: he ran a mail order business selling the things. Since they were cheap enough to market as souvenirs, they became fairly common fairly quickly. ...