Spirit photography

About 130 years before Photoshop was created, people had other methods in merging photos. But, that was a mystery to the most of the public - that's how it created countless possibilities. One of them was so-called "spirit photography". By a simple darkroom trick you could add a ghostly figure to someone's photo... imagine their reaction.

Source: http://monk3y.tumblr.com/post/11068745986/marianapparition-ectoplasms-spirit