These photo cards were designed for viewing through a Stereoscope, with a pair of separate images depicting a left and right eye view of the same scene creating a three dimensional image of the subject matter. The Stereoscope that is most commonly seen in today's market was created by Oliver Wendell Holmes in 1861, and consisted of two prismatic lens and a wooden hand held stand. The cards are held in place by iron frames at both ends, and the viewer slides back and forth to adjust the focus for the viewer. I have here several "sets" of cards, each with a different subject matter; 15 Biblical Scenes in color from the Life of Jesus; 9 Color Scenes from Russia; 9 Comic Scenes from 'The Newlywed's New Maid"; and 12 Comic Scenes from the Keystone Company, dated 1906; and 5 cards from the series on Greenwood Cemetery in Brooklyn, New York. All of the cards are standard size (3 1/2" x 7") and come in a nice wooden box which measures 7 3/4" x 9" x 5" in height. A great addition to any collection, or a great beginner's collection!